This projection of total PNMs isn't surprising if you consider that over the past decade+ the percentage of Greek students has steadily hung around 20-24%. The University has been growing the student population over the same period, thus an equivalent number of students pursuing Greek life.
True that...I don't consider 20% a particularly high ratio, either. 25% would be a little more normal...40-50% exceptionally high!
20% greek means, of course that 80% of the student body is NOT greek.