We know that lots of people, some 200 million already, are watching these Olympics. But just who are they?

Broadcast primetime Games viewers tend to be female and in their late 40s, and they favor swimming and gymnastics, according to Nielsen numbers crunched by Magna, the giant New York ad buying agency.

Interestingly, though, while more women than men are watching the Games, the men are driving more of the gains over Athens four years ago. The men’s total viewers rating is up 18 percent over 2004, compared to 9 percent for women, through the first six days of the Games on NBC.

Women are averaging an 11.4 rating among total viewers for the Games, with men just behind at 10.1.

Ratings for women and men are highest in the adults 50-plus demographic, with women averaging a 16.3 rating and men averaging a 14.6.

Among adults 18-49, women are averaging a 10.9 to men’s 9.9, but the men have seen much bigger gains over Athens. They’re up 16 percent, from an 8.5, while women are up 6 percent, from a 10.3.

The median age of Olympic viewers has hovered around 48, hitting a high of 50 for the opening ceremonies and falling to 46 on day five, the night the U.S. women’s gymnastic team won its silver medal.

Ratings for the Games have peaked on women’s gymnastics competition nights. The two highest-rated evenings in households through the first six days of the Games were the women’s gymnastics team competition prelims on day three, which averaged an 18.1 rating, and finals on day five, which averaged a 19.9.

Each day also featured swimming, and all but one were up compared to the same nights in Athens four years ago.

The Games have given NBC a huge ratings jolt overall. For the week ended Aug. 17, the network had the biggest advantage over the second-place finisher, 638 percent, among adults 18-49 in people meter history, dating back to 1987.

It also had the biggest weekly advantage over the combined Big Four competition, averaging a 9.6 to their 3.6, in at least 21 years.

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Meanwhile, in broadcast ratings for the week ended Aug. 17:
 
Among adults 18-49, NBC was first with a 9.6 rating and a 27 share, followed by CBS at 1.3/4, Fox at 1.2/4, ABC at 1.213, CW at 0.6/2 and MyNetworkTV at 0.3/1.
 
Among adults 18-34, NBC was first with a 7.9 average rating and a 25 share, followed by Fox at 1.0/4, ABC and CBS at 0.9/3, CW at 0.5/2 and MyNetworkTV at 0.3/1.
  
Among adults 25-54, NBC was first with a 10.9 average rating and a 28 share, followed by CBS at 1.7/5, Fox at 1.3/4, ABC at 1.3/3, CW at 0.6/1 and MyNetworkTV at 0.4/1.
 
Top five English-language Big Five shows (18-49s): 1. NBC’s “Olympics – Tuesday Prime” 12.4; Tie-2. NBC’s “Olympics – Monday Prime” and “Olympics – Saturday Prime” 10.6; 4. NBC’s “Olympics – Thursday Prime” 10.4; 5. NBC’s “Olympics – Wednesday Prime” 9.4.
 
Top five English-language Big Five shows (total viewers): 1. NBC’s “Olympics – Tuesday Prime” 34.01 million; 2. NBC’s “Olympics – Saturday Prime” 31.59 million; 3. “Olympics – Monday Prime” 30.17 million; 4. NBC’s “Olympics – Thursday Prime” 29.71 million; 5. NBC’s “Olympics – Wednesday Prime” 27.66 million.
 
Top five Live+7 English-language Big Five shows (households, week ended Aug. 3): 1. NBC’s “America’s Got Talent” 8.5; 2. CBS’s “Two and a Half Men” 6.3; 3. Fox’s “So You Think You Can Dance –Wednesday” 6.1; 4. CBS’s “CSI: Miami” 6.0; Tie-5. Fox’s “So You Think You Can Dance - Wednesday” and CBS’s “Criminal Minds” and “NCIS” 5.9.
 
Top five Live+7 English-language Big Five shows (18-49s, week ended Aug. 3): 1. NBC’s “America’s Got Talent” 4.0; 2. ABC’s “Wipeout” 3.9; 3. Fox’s “So You Think You Can Dance – Wednesday” 3.4; 4. Fox’s “So You Think You Can Dance – Thursday” 3.2; 5. CBS’s “Two and a Half Men” 3.0.
 
Show on the rise: “Friday Night Smackdown,” CW, Friday 8 p.m. “Smackdown” was able to grow week-to-week among 18-49s despite facing the Olympics, up 27 percent from a 1.1 to a 1.4.
 
Show on the decline: “Olympics – Sunday Prime,” NBC, Sunday 7:30 p.m. With Michael Phelps finishing his record-setting run the night before, Sunday’s coverage posted a 9.2 among 18-49s, still excellent but off 18 percent from an 11.2 for the previous Sunday’s Phelps-ful Olympics coverage.