用css给tbody加垂直滚动条的具体思路及样式代码

<table class="table">
<thead>
<tr>
<th>Id</th>
<th>Name</th>
<th>Category</th>
<th>MonthAmount</th>
<th>hasBackUp</th>
<th>score</th>
</tr>
</thead>
<tbody>
<tr>
<td>23</td>
<td>South Bearing</td>
<td>Glass/Material</td>
<td>1234444</td>
<td>TRUE</td>
<td>3456.00</td>
</tr>
<tr>
<td>23</td>
<td>South Bearing</td>
<td>Glass/Material</td>
<td>1234444</td>
<td>TRUE</td>
<td>3456.00</td>
</tr>
<tr>
<td>23</td>
<td>South Bearing</td>
<td>Glass/Material</td>
<td>1234444</td>
<td>TRUE</td>
<td>3456.00</td>
</tr>
<tr>
<td>23</td>
<td>South Bearing</td>
<td>Glass/Material</td>
<td>1234444</td>
<td>TRUE</td>
<td>3456.00</td>
</tr>
<tr>
<td>23</td>
<td>South Bearing</td>
<td>Glass/Material</td>
<td>1234444</td>
<td>TRUE</td>
<td>3456.00</td>
</tr>
<tr>
<td>23</td>
<td>South Bearing</td>
<td>Glass/Material</td>
<td>1234444</td>
<td>TRUE</td>
<td>3456.00</td>
</tr>
<tr>
<td>23</td>
<td>South Bearing</td>
<td>Glass/Material</td>
<td>1234444</td>
<td>TRUE</td>
<td>3456.00</td>
</tr>
<tr>
<td>23</td>
<td>South Bearing</td>
<td>Glass/Material</td>
<td>1234444</td>
<td>TRUE</td>
<td>3456.00</td>
</tr>
<tr>
<td>23</td>
<td>South Bearing</td>
<td>Glass/Material</td>
<td>1234444</td>
<td>TRUE</td>
<td>3456.00</td>
</tr>
<tr>
<td>23</td>
<td>South Bearing</td>
<td>Glass/Material</td>
<td>1234444</td>
<td>TRUE</td>
<td>3456.00</td>
</tr>
<tr>
<td>23</td>
<td>South Bearing</td>
<td>Glass/Material</td>
<td>1234444</td>
<td>TRUE</td>
<td>3456.00</td>
</tr>
</tbody>
</table>

.table thead tr {
display:block;
}
.table tbody {
display: block;
height: 200px;
overflow: auto;
}
.table th {
width:20%;
}
.table td {
width:20%;
}