adding attribute values

I need assistance on getting my template to add the attribute values of
"person". I tried using the format-number, but I'm falling short on what
the second argument would be.

Any help is appreciated.
Thanks, Max


XSLT 1.0 SAXON6.5.5



<xsl:template match="person">
      	<tr>
          	<td width="40%" valign="top"
class="SubSectionHeader">Personnel:</td>
            <td align="left"><xsl:value-of
select="format-number(sum(@man))"/> men are required</td>
      	</tr>
</xsl:template>

Example:

<person man='1'>
<person man='6'>
<person man='2'>

Desired result:
Personnel:
9 men are required