Chart creator u/theimpossiblesalad explained, "The Natsal surveys are some of the largest surveys of sexual behavior in the world. Since 1990, the surveys take place in Britain once every 10 years. The respondents are selected randomly, and thus the results are broadly representative of the British general population.
"For the chart above, I used data from the Natsal-3 survey, conducted between 2010 and 2012. The younger respondents (16–24 years old) were peripubescent between 1998 and 2008, when the internet was not a part of their everyday lives.
"As such, just 4% of men and 2% of women list the internet as their main source of sexual education. This will be further explored on the Natsal-4 survey, which was previously planned for May 2020 and is now scheduled for the upcoming summer."