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:
Raymond Smith Dugan
Table title:

Table:
<table id='hittask' contenteditable='False'>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > 497 Iva </td><td class="highlighted"  colspan=1 rowspan=1 > 4 November 1902 </td><td colspan=1 rowspan=1 > list </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > 503 Evelyn </td><td class="highlighted"  colspan=1 rowspan=1 > 19 January 1903 </td><td colspan=1 rowspan=1 > list </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > 506 Marion </td><td class="highlighted"  colspan=1 rowspan=1 > 17 February 1903 </td><td colspan=1 rowspan=1 > list </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > 507 Laodica </td><td class="highlighted"  colspan=1 rowspan=1 > 19 February 1903 </td><td colspan=1 rowspan=1 > list </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > 508 Princetonia </td><td class="highlighted"  colspan=1 rowspan=1 > 20 April 1903 </td><td colspan=1 rowspan=1 > list </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > 510 Mabella </td><td class="highlighted"  colspan=1 rowspan=1 > 20 May 1903 </td><td colspan=1 rowspan=1 > list </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > 511 Davida </td><td class="highlighted"  colspan=1 rowspan=1 > 30 May 1903 </td><td colspan=1 rowspan=1 > list </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > 516 Amherstia </td><td class="highlighted"  colspan=1 rowspan=1 > 20 September 1903 </td><td colspan=1 rowspan=1 > list </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > 517 Edith </td><td class="highlighted"  colspan=1 rowspan=1 > 22 September 1903 </td><td colspan=1 rowspan=1 > list </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > 518 Halawe </td><td class="highlighted"  colspan=1 rowspan=1 > 20 October 1903 </td><td colspan=1 rowspan=1 > list </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > 519 Sylvania </td><td class="highlighted"  colspan=1 rowspan=1 > 20 October 1903 </td><td colspan=1 rowspan=1 > list </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > 521 Brixia </td><td class="highlighted"  colspan=1 rowspan=1 > 10 January 1904 </td><td colspan=1 rowspan=1 > list </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > 523 Ada </td><td class="highlighted"  colspan=1 rowspan=1 > 27 January 1904 </td><td colspan=1 rowspan=1 > list </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > 533 Sara </td><td class="highlighted"  colspan=1 rowspan=1 > 19 April 1904 </td><td colspan=1 rowspan=1 > list </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > 534 Nassovia </td><td class="highlighted"  colspan=1 rowspan=1 > 19 April 1904 </td><td colspan=1 rowspan=1 > list </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > 535 Montague </td><td class="highlighted"  colspan=1 rowspan=1 > 7 May 1904 </td><td colspan=1 rowspan=1 > list </td></tr>
</table>
Question:
How many asteroids did Dugan discover?
Answer:
Dugan discovered 16 asteroids between 1902 and 1904, including 511 Davida.