In an earlier post, the student counts for grade twelve used spring portfolio numbers in three years and then fall on-demand numbers for the last two. Using spring numbers consistently doesn't change that post's main point about ninth grade, but it does provide a better comparison of numbers of students getting close to graduation. So, here's a graph for the class of 2008 done that way:
And here's a chart of the five most recent classes:
And here's a PDF download if you want a graph showing the full set of trends.