Um, you missed his clarification:
"One reason for the lower national average could be more schools in Division I". The data was average, not total which fact did not decrease the past 6 years:
http://fs.ncaa.org/Docs/stats/m_bask...ttend/2013.pdf
But while we're on the topic of declining attendance over those 6 years......
http://www.timesfreepress.com/news/2...ance-declines/