Also, it says "About 1,000 students will have taken the course by the end of the year, with more than 75 percent of students passing through a computer science

Also, it says "About 1,000 students will have taken the course by the end of the year, with more than 75 percent of students passing through a computer science introductory course before the end of their time at Stanford." which makes it much more normal for there being a high number of cheaters. A lot of people are taking the course, so there are a lot more cheaters although the proportion might be the same. (I don't know if this is actually the case.)