Please read the following table in HTML format from a webpage and then answer the question in detail according to the table. Each table cell is defined by a <td> and a </td> tag. Each table row starts with a <tr> and ends with a </tr> tag. 'rowspan=m' and 'colspan=n' represents a cell spaning over 'm' rows and 'n' columns.

Webpage title:
Vancouver Grizzlies
Table title:
Season-by-season record
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=2 > Season </th><th colspan=5 rowspan=1 > Regular season </th><th colspan=1 rowspan=2 > Postseason </th><th colspan=1 rowspan=2 > Attendance </th><th colspan=1 rowspan=2 > Ref </th></tr>
<tr> <th colspan=1 rowspan=1 > Pos </th><th colspan=1 rowspan=1 > GP </th><th colspan=1 rowspan=1 > W </th><th colspan=1 rowspan=1 > L </th><th colspan=1 rowspan=1 > Win% </th></tr>
<tr> <td colspan=1 rowspan=1 > 1995–96 </td><td colspan=1 rowspan=1 > 7th </td><td colspan=1 rowspan=1 > 82 </td><td colspan=1 rowspan=1 > 15 </td><td colspan=1 rowspan=1 > 67 </td><td colspan=1 rowspan=1 > .183 </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > 17,183 </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > 1996–97 </td><td colspan=1 rowspan=1 > 7th </td><td colspan=1 rowspan=1 > 82 </td><td colspan=1 rowspan=1 > 14 </td><td colspan=1 rowspan=1 > 68 </td><td colspan=1 rowspan=1 > .171 </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > 16,571 </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > 1997–98 </td><td colspan=1 rowspan=1 > 6th </td><td colspan=1 rowspan=1 > 82 </td><td colspan=1 rowspan=1 > 19 </td><td colspan=1 rowspan=1 > 63 </td><td colspan=1 rowspan=1 > .232 </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > 16,108 </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > 1998–99 </td><td colspan=1 rowspan=1 > 7th </td><td colspan=1 rowspan=1 > 50 </td><td colspan=1 rowspan=1 > 8 </td><td colspan=1 rowspan=1 > 42 </td><td colspan=1 rowspan=1 > .160 </td><td colspan=1 rowspan=1 > — </td><td class="highlighted"  colspan=1 rowspan=1 > 16,718 </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > 1999–00 </td><td colspan=1 rowspan=1 > 7th </td><td colspan=1 rowspan=1 > 82 </td><td colspan=1 rowspan=1 > 22 </td><td colspan=1 rowspan=1 > 60 </td><td colspan=1 rowspan=1 > .268 </td><td colspan=1 rowspan=1 > — </td><td class="highlighted"  colspan=1 rowspan=1 > 13,899 </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > 2000–01 </td><td colspan=1 rowspan=1 > 7th </td><td colspan=1 rowspan=1 > 82 </td><td colspan=1 rowspan=1 > 23 </td><td colspan=1 rowspan=1 > 59 </td><td colspan=1 rowspan=1 > .280 </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > 13,737 </td><td colspan=1 rowspan=1 >  </td></tr>
</table>
Question:
What happened to attendance during the 1999-00 season?
Answer:
The 1999–00 season saw a large drop in attendance, averaging 13,899.