<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<div class="d-table">
<div class="d-table-cell">
<div class="container">
<div class='selector'>
<ul>
<li>
<input id='c1' type='checkbox'>
<label for='c1'>District 1</label>
</li>
<li>
<input id='c2' type='checkbox'>
<label for='c2'>District 2</label>
</li>
<li>
<input id='c3' type='checkbox'>
<label for='c3'>District 3</label>
</li>
<li>
<input id='c4' type='checkbox'>
<label for='c4'>District 4</label>
</li>
<li>
<input id='c5' type='checkbox'>
<label for='c5'>District 5</label>
</li>
<li>
<input id='c6' type='checkbox'>
<label for='c6'>District 6</label>
</li>
<li>
<input id='c7' type='checkbox'>
<label for='c7'>District 7</label>