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When it comes to sex, there are a million different numbers—from the average length of time it lasts to the number of calories a romp in the sack burns. We compiled the most interesting statistics on the topic, and ran them by our experts to see what they really mean for you.

84: Percentage of women who say they have sex to get their man to help out around the house.
Surprising, right? But wait for this: Sexual health experts say a little harmless "sexual bribery" in a healthy relationship is a good thing. "Considering that women still end up bearing an unequal distribution of labor on the domestic front, turning foreplay into 'choreplay' is a brilliant strategy," says Ian Kerner, PhD, a sex and relationship expert and the author of She Comes First: The Thinking Man's Guide to Pleasuring a Woman. "Studies have shown that women are more likely to be interested in sex if the house is clean, so this should be motivation enough for men to grab a mop and load the dishwasher."

3.5: Average size in inches for a non-erect penis.
"Most men think they're either too small or too big, when in fact they're average," says Dr. Kerner. "3.5 inches non-erect equals 5 inches or so erect. Considering that most of the nerve endings that contribute to the female orgasm are located on the surface of the vulva and within the first two inches of the vaginal canal, average is more than enough." And, according to his research, most women aren't that concerned about size anyway. "The vast majority [of women] rated a clean penis as being more important than a big penis." So forget the pills and pumps, guys, and instead just take a shower!

200: Number of calories the average person burns during 30 minutes of sexual intercourse.
Skip the gym and have sex? Don't break up with your elliptical machine just yet, says Gilda Carle, PhD, a sex and relationship expert and the author of How to Win When Your Mate Cheats. "Sex may be exercise, but it's not enough exercise to burn your thunder thighs. Make sex an addition to your routine."

20: Percentage of Americans who have had sex with a coworker.
Say you have a crush on someone at the office. Is it ever OK to act on it? "Now that the vast majority of women work, it only makes sense that the workplace is becoming a hotbed of sexual activity," says Dr. Kerner. "First off, most affairs now occur between coworkers. And those people who are still single are spending more and more time at work, so it only makes sense that with limited time comes a limited pool of candidates." While not all office relationships are doomed, there are certain types that Dr. Kerner says to watch out for. "If you're married, watch out for the flirty friendships that lead to emotional infidelity and then sexual infidelity. If you're single and interested in someone at work, make sure that he's in a different department and certainly not anyone you report to or who reports to you." Bottom line, he says: "Proceed with caution across the work-sex boundary."

2: The number of minutes before ejaculation that qualifies as premature.
Premature ejaculation (PE) is more common than erectile disorder, and some studies estimate that 1 in 3 men experience it, says Dr. Kerner. "It doesn't mean a guy is lazy, selfish or immature," he says. "In fact, most of the latest science is showing that it could be genetic. Many guys who suffer from PE don't even make it to intercourse, they ejaculate during foreplay." While there isn't a "little blue pill" for the condition yet, Dr. Kerner says that some behavioral therapies can help, as well as medication such as Paxil, which is thought to delay ejaculation. And, he says to remember: "There are many paths to the female orgasm."

25: Percentage of Americans who are living with an incurable STD.
The point here? Simple, says Dr. Carle: "Always take care of your own sexual health. If you have suspicions, get tested more frequently. Knowing your body as well as your partner's and using honesty, sensitivity and safe sex can ensure your love is the focus, rather than your disease." STDs can also be transmitted during oral sex, so being in a trusting monogamous relationship is the best way to protect yourself, adds Dr. Kerner. "From HPV to chlamydia, consider a full screening at your next physical," he says.

12: Percentage of married people who sleep alone.
Here's a shocker: In some cases, sleeping apart could be healthier! "Many couples sleep alone for different reasons," says Dr. Kerner. "A spouse who snores, kids in the bed—in the long run a good night's sleep may be more important to your health than an interrupted night in a shared bed." But here's the catch: If you're not sharing a bed, you should be making time for sex and intimacy. He says, "If you're not sleeping in the same bed, for whatever reason, you are less likely to have sex and more likely to find yourself in a rut and then vulnerable to issues like infidelity."

20: Number of minutes the average couple spends on foreplay.
Foreplay, says Dr. Carle, "extends a couple's intimacy and it also prevents a woman from feeling used and unfulfilled." So, she says, the more the merrier. Women generally take longer to get aroused than men, adds Dr. Kerner, and the difference between 10 minutes and 20 minutes of foreplay could be the difference between being in a satisfying relationship and not. Remember, he says, "the skin is our largest body organ, and the possibilities for exploration are unlimited. Also, the brain is the biggest sex organ, so talking about sex and sharing a sexy thought is also foreplay."

103: Number of times per year that the average person has sex.
"People always wonder how often they should be having sex, and there's no right number," says Dr. Kerner. "In general, sex begets sex, and sex ruts beget sex ruts. If you focus on having sex once a week, you're probably going to end up having it more often as you'll be more tuned in and generally turned on." Dr. Kerner adds that women who have sex semi-regularly—at least once a week—experience increased testosterone levels, which can lead to a healthier, more vigorous sex drive. If you're wondering if you should make a move on your husband tonight, Dr. Kerner says "yes!" He adds, "Try it—you'll like it."

48: Percentage of women who say they have faked an orgasm at least once in their life.
While there may be a time and a place for faking, it's not the preferred route of sex experts—and it could signal some relationship issues that need to be addressed. "If you're with a partner you care to be with, what is the payoff to faking it?" asks Dr. Carle. "If you can't get turned on, probe what the reason is. Are you disinterested in sex? Do you have other things on your mind? Do you dislike your partner? Are you angry with him? Your body often says what your mind won't admit." Fakers, beware, adds Dr. Kerner: "It's a slippery slope and often leads to more faking, the buildup of anger and resentment, and a lack of enjoyment and interest in sex. Rather than faking, better to be in the kind of relationship where it's OK if you don't always have an orgasm and you can talk about the reasons. Every time someone fakes it there's a lost opportunity to communicate and make sex—and your relationship—better."

48: Percentage of Americans who report being satisfied with their sex life.
If there's anything about this statistic that you should remember, it's this: You're normal. "Life is not a romantic comedy," says Dr. Carle. "Sometimes you're into sex, and other times you're not. But the real satisfaction from which great sex emanates is the relationship you have before the sex occurs. Deep, loving friendship, feelings of safety and knowing that you can say 'no' when you are not in the mood all trump momentary orgasm." She's quick to remind women that it's the relationship and love that counts, rather than "what Hollywood shows us to be a quick roll in the hay."

Sarah Jio is the health and fitness blogger for Glamour.com. Visit her blog, Vitamin G.

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