How to add space between two rows with border in bootstrap table

table{ width: 100%;max-width: 100%;  margin-bottom: 20px;border:solid 1px #000; border-collapse: collapse;}

tbody tr{border:2px solid #256ac4;}
td{    color: #8d9097; vertical-align: top; font-size: 14px;}
th{text-align:left}

<table>
<thead>
     <th>A</th>
     <th>B</th>
     <th>C</th>
</thead>
<tbody>
  <tr>
    <td>AA</td>
     <td>AA</td>
      <td>AA</td>
  </tr>
 <tr>
    <td>AA</td>
     <td>AA</td>
      <td>AA</td>
  </tr>
 <tr>
    <td>AA</td>
     <td>AA</td>
      <td>AA</td>
  </tr>

</tbody>

</table>