Anyway add this code above {$sidebar} in your index template.
Code:
<table border="0" cellspacing="{$theme['borderwidth']}" cellpadding="{$theme['tablespace']}" class="tborder">
<tr>
<td class="thead"><strong>Board Statistics</strong></td>
</tr>
<tr>
<td class="trow1" style="padding:10px;">
<div style="float: left;display: inline-block">
Total Threads:
</div>
<div style="float: right;display: inline-block">
{$stats['numusers']}
</div>
</td>
</tr>
<tr>
<td class="trow1" style="padding:10px;">
<div style="float: left;display: inline-block">
Total Posts:
</div>
<div style="float: right;display: inline-block">
{$stats['numposts']}
</div>
</td>
</tr>
<tr>
<td class="trow1" style="padding:10px;">
<div style="float: left;display: inline-block">
Total Members:
</div>
<div style="float: right;display: inline-block">
{$stats['numusers']}
</div>
</td>
</tr>
<tr>
<td class="trow1" style="padding:10px;">
<div style="float: left;display: inline-block">
Most Online:
</div>
<div style="float: right;display: inline-block">
{$mostonline['numusers']}
</div>
</td>
</tr>
</table>
<br />
And expecto patronum you have the stats in the sidebar