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:
Shin Hye-sun
Table title:
Television series
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=1 > Year </th><th colspan=1 rowspan=1 > Title </th><th colspan=1 rowspan=1 > Role </th><th colspan=1 rowspan=1 > Network </th><th colspan=1 rowspan=1 > Notes </th></tr>
<tr> <td colspan=1 rowspan=1 > 2012–2013 </td><td colspan=1 rowspan=1 > School 2013 </td><td colspan=1 rowspan=1 > Shin Hye-sun </td><td colspan=1 rowspan=1 > KBS2 </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=2 > 2014 </td><td colspan=1 rowspan=1 > Angel Eyes </td><td colspan=1 rowspan=1 > young Cha Min-soo </td><td colspan=1 rowspan=1 > SBS </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > High School King of Savvy </td><td colspan=1 rowspan=1 > Go Yoon-joo </td><td colspan=1 rowspan=1 > tvN </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > 2014–2015 </td><td colspan=1 rowspan=1 > Forever Young </td><td colspan=1 rowspan=1 > Han Mi-so </td><td colspan=1 rowspan=1 > VTV </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=2 > 2015 </td><td colspan=1 rowspan=1 > Oh My Ghost </td><td colspan=1 rowspan=1 > Kang Eun-hee </td><td colspan=1 rowspan=1 > tvN </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > She Was Pretty </td><td colspan=1 rowspan=1 > Han Seol </td><td colspan=1 rowspan=1 > MBC </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=2 > 2016 </td><td colspan=1 rowspan=1 > Five Enough </td><td colspan=1 rowspan=1 > Lee Yeon-tae </td><td colspan=1 rowspan=1 > KBS2 </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > Legend of the Blue Sea </td><td colspan=1 rowspan=1 > Cha Si-ah </td><td colspan=1 rowspan=1 > SBS </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > 2017 </td><td colspan=1 rowspan=1 > Stranger </td><td colspan=1 rowspan=1 > Young Eun-soo </td><td colspan=1 rowspan=1 > tvN </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > 2017–2018 </td><td colspan=1 rowspan=1 > My Golden Life </td><td colspan=1 rowspan=1 > Seo Ji-an </td><td colspan=1 rowspan=1 > KBS2 </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=2 > 2018 </td><td colspan=1 rowspan=1 > Still 17 </td><td colspan=1 rowspan=1 > Woo Seo-ri </td><td colspan=1 rowspan=2 > SBS </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > The Hymn of Death </td><td class="highlighted"  colspan=1 rowspan=1 > Yun Sim-deok </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > 2019 </td><td colspan=1 rowspan=1 > Angel's Last Mission: Love </td><td colspan=1 rowspan=1 > Lee Yeon-seo </td><td colspan=1 rowspan=1 > KBS2 </td><td colspan=1 rowspan=1 >  </td></tr>
</table>
Question:
What network cast Shin Hye-sun the most frequently?
Answer:
Shin Hye-sun was cast by KBS2 in the series School 2013, Five enough, My Golden Life, and Angel's Last Mission: Love, for a total of 4 series.