Passage: The frequency of nocturnal emissions is highly variable. Some reported that it is due to being sexually inactive for a period of 1–2 weeks, with no engagement in either intercourse or masturbation. Some males have experienced large numbers of nocturnal emissions as teenagers, while others have never experienced one. In the U.S., 83% of men experience nocturnal emissions at some time in their life. For males who have experienced nocturnal emissions the mean frequency ranges from 0.36 times per week (about once every three weeks) for single 15-year-old males to 0.18 times per week (about once every five-and-a-half weeks) for 40-year-old single males. For married males the mean ranges from 0.23 times per week (about once per month) for 19-year-old married males to 0.15 times per week (about once every two months) for 50-year-old married males. In some parts of the world nocturnal emissions are more common. For example, in Indonesia surveys have shown that 97% of men experience nocturnal emissions by the age of 24.Some males have the emissions only at a certain age, while others have them throughout their lives following puberty. The frequency with which one has nocturnal emissions has not been conclusively linked to frequency of masturbation. Alfred Kinsey found there may be "some correlation between the frequencies of masturbation and the frequencies of nocturnal emissions. In general the males who have the highest frequencies of nocturnal emissions may have somewhat lower rates of masturbation."

Question: For guys who possess nighttime emissions what is the mean frequency or someone who is 15 and single?
0.36 times per week