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:
Ronald de Boer
Table title:
Club
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=3 rowspan=1 > Club performance </th><th colspan=2 rowspan=1 > League </th><th colspan=2 rowspan=1 > Cup </th><th colspan=2 rowspan=1 > League Cup </th><th colspan=2 rowspan=1 > Continental </th><th colspan=2 rowspan=1 > Total </th></tr>
<tr> <th colspan=1 rowspan=1 > Season </th><th colspan=1 rowspan=1 > Club </th><th colspan=1 rowspan=1 > League </th><th colspan=1 rowspan=1 > Apps </th><th colspan=1 rowspan=1 > Goals </th><th colspan=1 rowspan=1 > Apps </th><th colspan=1 rowspan=1 > Goals </th><th colspan=1 rowspan=1 > Apps </th><th colspan=1 rowspan=1 > Goals </th><th colspan=1 rowspan=1 > Apps </th><th colspan=1 rowspan=1 > Goals </th><th colspan=1 rowspan=1 > Apps </th><th colspan=1 rowspan=1 > Goals </th></tr>
<tr> <th colspan=3 rowspan=1 > Netherlands </th><th colspan=2 rowspan=1 > League </th><th colspan=2 rowspan=1 > KNVB Cup </th><th colspan=2 rowspan=1 > Super Cup </th><th colspan=2 rowspan=1 > Europe </th><th colspan=2 rowspan=1 > Total </th></tr>
<tr> <td colspan=1 rowspan=1 > 1987–88 </td><td class="highlighted"  colspan=1 rowspan=4 > Ajax </td><td class="highlighted"  colspan=1 rowspan=4 > Eredivisie </td><td colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 > 1 </td></tr>
<tr> <td colspan=1 rowspan=1 > 1988–89 </td><td colspan=1 rowspan=1 > 17 </td><td colspan=1 rowspan=1 > 5 </td><td colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 18 </td><td colspan=1 rowspan=1 > 5 </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > 1989–90 </td><td colspan=1 rowspan=1 > 20 </td><td colspan=1 rowspan=1 > 7 </td><td colspan=1 rowspan=1 > 3 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 2 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 > 25 </td><td colspan=1 rowspan=1 > 7 </td></tr>
<tr> <td colspan=1 rowspan=1 > 1990–91 </td><td colspan=1 rowspan=1 > 14 </td><td colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 > 3 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 17 </td><td colspan=1 rowspan=1 > 1 </td></tr>
<tr> <td colspan=1 rowspan=1 > 1991–92 </td><td colspan=1 rowspan=2 > Twente </td><td colspan=1 rowspan=2 > Eredivisie </td><td colspan=1 rowspan=1 > 33 </td><td colspan=1 rowspan=1 > 11 </td><td colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 34 </td><td colspan=1 rowspan=1 > 11 </td></tr>
<tr> <td colspan=1 rowspan=1 > 1992–93 </td><td colspan=1 rowspan=1 > 16 </td><td colspan=1 rowspan=1 > 11 </td><td colspan=1 rowspan=1 > 2 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 18 </td><td colspan=1 rowspan=1 > 11 </td></tr>
<tr> <td colspan=1 rowspan=1 > 1992–93 </td><td colspan=1 rowspan=7 > Ajax </td><td colspan=1 rowspan=7 > Eredivisie </td><td colspan=1 rowspan=1 > 15 </td><td colspan=1 rowspan=1 > 5 </td><td colspan=1 rowspan=1 > 3 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 18 </td><td colspan=1 rowspan=1 > 5 </td></tr>
<tr> <td colspan=1 rowspan=1 > 1993–94 </td><td colspan=1 rowspan=1 > 28 </td><td colspan=1 rowspan=1 > 5 </td><td colspan=1 rowspan=1 > 4 </td><td colspan=1 rowspan=1 > 2 </td><td colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 > 6 </td><td colspan=1 rowspan=1 > 2 </td><td colspan=1 rowspan=1 > 39 </td><td colspan=1 rowspan=1 > 9 </td></tr>
<tr> <td colspan=1 rowspan=1 > 1994–95 </td><td colspan=1 rowspan=1 > 25 </td><td colspan=1 rowspan=1 > 5 </td><td colspan=1 rowspan=1 > 3 </td><td colspan=1 rowspan=1 > 4 </td><td colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 > 10 </td><td colspan=1 rowspan=1 > 2 </td><td colspan=1 rowspan=1 > 39 </td><td colspan=1 rowspan=1 > 11 </td></tr>
<tr> <td colspan=1 rowspan=1 > 1995–96 </td><td colspan=1 rowspan=1 > 31 </td><td colspan=1 rowspan=1 > 7 </td><td colspan=1 rowspan=1 > 2 </td><td colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 > 11 </td><td colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 > 45 </td><td colspan=1 rowspan=1 > 9 </td></tr>
<tr> <td colspan=1 rowspan=1 > 1996–97 </td><td colspan=1 rowspan=1 > 28 </td><td colspan=1 rowspan=1 > 5 </td><td colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 > 10 </td><td colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 > 40 </td><td colspan=1 rowspan=1 > 6 </td></tr>
<tr> <td colspan=1 rowspan=1 > 1997–98 </td><td colspan=1 rowspan=1 > 30 </td><td colspan=1 rowspan=1 > 7 </td><td colspan=1 rowspan=1 > 5 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 8 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 > 43 </td><td colspan=1 rowspan=1 > 7 </td></tr>
<tr> <td colspan=1 rowspan=1 > 1998–99 </td><td colspan=1 rowspan=1 > 15 </td><td colspan=1 rowspan=1 > 2 </td><td colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 6 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 > 22 </td><td colspan=1 rowspan=1 > 2 </td></tr>
<tr> <th colspan=3 rowspan=1 > Spain </th><th colspan=2 rowspan=1 > League </th><th colspan=2 rowspan=1 > Copa del Rey </th><th colspan=2 rowspan=1 > Super Cup </th><th colspan=2 rowspan=1 > Europe </th><th colspan=2 rowspan=1 > Total </th></tr>
<tr> <td colspan=1 rowspan=1 > 1998–99 </td><td colspan=1 rowspan=2 > Barcelona </td><td colspan=1 rowspan=2 > La Liga </td><td colspan=1 rowspan=1 > 13 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 > 4 </td><td colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 17 </td><td colspan=1 rowspan=1 > 1 </td></tr>
<tr> <td colspan=1 rowspan=1 > 1999–2000 </td><td colspan=1 rowspan=1 > 20 </td><td colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 > 5 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 > 11 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 > 37 </td><td colspan=1 rowspan=1 > 2 </td></tr>
<tr> <th colspan=3 rowspan=1 > Scotland </th><th colspan=2 rowspan=1 > League </th><th colspan=2 rowspan=1 > Scottish Cup </th><th colspan=2 rowspan=1 > League Cup </th><th colspan=2 rowspan=1 > Europe </th><th colspan=2 rowspan=1 > Total </th></tr>
<tr> <td colspan=1 rowspan=1 > 2000–01 </td><td colspan=1 rowspan=4 > Rangers </td><td colspan=1 rowspan=4 > Premier League </td><td colspan=1 rowspan=1 > 17 </td><td colspan=1 rowspan=1 > 6 </td><td colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 > 7 </td><td colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 > 24 </td><td colspan=1 rowspan=1 > 7 </td></tr>
<tr> <td colspan=1 rowspan=1 > 2001–02 </td><td colspan=1 rowspan=1 > 25 </td><td colspan=1 rowspan=1 > 8 </td><td colspan=1 rowspan=1 > 4 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 > 3 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 > 7 </td><td colspan=1 rowspan=1 > 2 </td><td colspan=1 rowspan=1 > 39 </td><td colspan=1 rowspan=1 > 10 </td></tr>
<tr> <td colspan=1 rowspan=1 > 2002–03 </td><td colspan=1 rowspan=1 > 33 </td><td colspan=1 rowspan=1 > 16 </td><td colspan=1 rowspan=1 > 5 </td><td colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 > 3 </td><td colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 > 2 </td><td colspan=1 rowspan=1 > 2 </td><td colspan=1 rowspan=1 > 43 </td><td colspan=1 rowspan=1 > 20 </td></tr>
<tr> <td colspan=1 rowspan=1 > 2003–04 </td><td colspan=1 rowspan=1 > 16 </td><td colspan=1 rowspan=1 > 2 </td><td colspan=1 rowspan=1 > 2 </td><td colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 > 2 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 > 21 </td><td colspan=1 rowspan=1 > 3 </td></tr>
<tr> <th colspan=3 rowspan=1 > Qatar </th><th colspan=2 rowspan=1 > League </th><th colspan=2 rowspan=1 > Emir of Qatar Cup </th><th colspan=2 rowspan=1 > Qatari Stars Cup </th><th colspan=2 rowspan=1 > Asia </th><th colspan=2 rowspan=1 > Total </th></tr>
<tr> <td colspan=1 rowspan=1 > 2004–05 </td><td colspan=1 rowspan=1 > Al-Rayyan </td><td colspan=1 rowspan=1 > Qatar Stars League </td><td colspan=1 rowspan=1 > 22 </td><td colspan=1 rowspan=1 > 3 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 > 0 </td><td colspan=1 rowspan=1 > 22 </td><td colspan=1 rowspan=1 > 3 </td></tr>
<tr> <th colspan=1 rowspan=3 > Country </th><th colspan=2 rowspan=1 > Netherlands </th><th colspan=1 rowspan=1 > 272 </th><th colspan=1 rowspan=1 > 72 </th><th colspan=1 rowspan=1 > 29 </th><th colspan=1 rowspan=1 > 7 </th><th colspan=1 rowspan=1 > 4 </th><th colspan=1 rowspan=1 > 0 </th><th colspan=1 rowspan=1 > 53 </th><th colspan=1 rowspan=1 > 6 </th><th colspan=1 rowspan=1 > 358 </th><th colspan=1 rowspan=1 > 85 </th></tr>
<tr> <th colspan=2 rowspan=1 > Spain </th><th colspan=1 rowspan=1 > 33 </th><th colspan=1 rowspan=1 > 1 </th><th colspan=1 rowspan=1 > 9 </th><th colspan=1 rowspan=1 > 1 </th><th colspan=1 rowspan=1 > 1 </th><th colspan=1 rowspan=1 > 1 </th><th colspan=1 rowspan=1 > 11 </th><th colspan=1 rowspan=1 > 0 </th><th colspan=1 rowspan=1 > 54 </th><th colspan=1 rowspan=1 > 3 </th></tr>
<tr> <th colspan=2 rowspan=1 > Scotland </th><th colspan=1 rowspan=1 > 91 </th><th colspan=1 rowspan=1 > 32 </th><th colspan=1 rowspan=1 > 12 </th><th colspan=1 rowspan=1 > 2 </th><th colspan=1 rowspan=1 > 8 </th><th colspan=1 rowspan=1 > 1 </th><th colspan=1 rowspan=1 > 18 </th><th colspan=1 rowspan=1 > 5 </th><th colspan=1 rowspan=1 > 129 </th><th colspan=1 rowspan=1 > 40 </th></tr>
<tr> <th colspan=3 rowspan=1 > Total </th><th colspan=1 rowspan=1 > 396 </th><th colspan=1 rowspan=1 > 105 </th><th colspan=1 rowspan=1 > 50 </th><th colspan=1 rowspan=1 > 10 </th><th colspan=1 rowspan=1 > 13 </th><th colspan=1 rowspan=1 > 2 </th><th colspan=1 rowspan=1 > 72 </th><th colspan=1 rowspan=1 > 11 </th><th colspan=1 rowspan=1 > 531 </th><th colspan=1 rowspan=1 > 128 </th></tr>
</table>
Question:
What was Ronald de Boer doing in 1989-90?
Answer:
In 1989–90, Ronald de Boer appeared for Ajax in Eredivisie.