57

Source: The Big Necessity, Rose George,

1
In January 2002, a woman on an SAS flight from Oslo to New York made the mistake of flushing while she was still seated, creating such suction that the crew could do nothing to free her. It wasn’t until she landed in New York 7 hours later that ground technicians were able to pry her off. The story was featured in a London newspaper under the headline “PLANE GIRL’S LOO HORROR.”
Source: The People, 1/27/2002

2 years
On Feb. 27, 2008, police in Ness City, Kansas received a report from Gary McFarren that there was something wrong with his girlfriend. When they arrived at his trailer, they found his 35 year-old girlfriend, Nancy Barsock, on the toilet in the trailer's bathroom, where McFarren said she had spent the past two years because she felt comfortable in the room. The woman's skin on her rear end had grown around the toilet seat, which was pried off the toilet and transported along with her to the hospital, where it was removed from her body by doctors.
Source: Associated Press, 3/13/2008

12%
According to an Aug. 2007 study in which women were observed at public bathrooms across the U.S.
Source: Wall Street Journal, 2/15/2008