The tenth value was generated by a very poor study in a very long time ago by a man named Kinsey (1948) More recent studies generally place the upper boundary at 4 and the more likely boundary at 2 to 3 percent
http://www.washingtonpost.com/national/health-science/health-survey-gives-government-its-first-large-scale-data-on-gay-bisexual-population/2014/07/14/2db9f4b0-092f-11e4-bbf1-cc51275e7f8f_story.html