Filemaker XSL - inconsistent number of photo nodes in imported XML

I have an XML file like this which I need to import into a Filemaker database.

<propertys>
 <property>
  <ref>12345</ref>
  <photos>
   <photo>http://ift.tt/1wxvScx;
   <photo>http://ift.tt/1wxvScx;
  </photos>
 </property>
 <property>
  <ref>54321</ref>
  <photos>
   <photo>http://ift.tt/1wxvScx;
   <photo>http://ift.tt/1wxvScx;
   <photo>http://ift.tt/1wxvScx;
   <photo>http://ift.tt/1wxvScx;
  </photos>
 </property>
 <property>
  <ref>67890</ref>
  <photos>
   <photo>http://ift.tt/1wxvScx;
   <photo>http://ift.tt/1wxvScx;
   <photo>http://ift.tt/1wxvScx;
   <photo>http://ift.tt/1wxvScx;
   <photo>http://ift.tt/1wxvScx;
   <photo>http://ift.tt/1wxvScx;
   <photo>http://ift.tt/1wxvScx;
  </photos>
 </property>
</propertys>

As you can see, there is an inconsistent number of photos per property.

I need to fit this into the following Filemaker XSLT import structure, which has to give an output of 36 photo rows per property whether there are 36 photos or not.

<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://ift.tt/tCZ8VR" exclude-result-prefixes="xsl">
 <xsl:output method="xml" version="1.0" encoding="UTF-8" indent="yes"/>
 <xsl:template match="/">
  <FMPXMLRESULT xmlns="http://ift.tt/1ckTOKc">
  <ERRORCODE>0</ERRORCODE>
  <PRODUCT BUILD="" NAME="FileMaker" VERSION="ProAdvanced 12.0v4"/>
  <DATABASE DATEFORMAT="" LAYOUT="" NAME="" RECORDS="" TIMEFORMAT=""/>
  <METADATA>
    <FIELD EMPTYOK="NO" MAXREPEAT="1" NAME="Ref" TYPE="TEXT" />             
    <FIELD EMPTYOK="NO" MAXREPEAT="1" NAME="Image1" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image2" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image3" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image4" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image5" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image6" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image7" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image8" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image9" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image10" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image11" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image12" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image13" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image14" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image15" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image16" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image17" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image18" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image19" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image20" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image21" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image22" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image23" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image24" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image25" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image26" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image27" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image28" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image29" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image30" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image31" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image32" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image33" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image34" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image35" TYPE="TEXT" />
    <FIELD EMPTYOK="YES" MAXREPEAT="1" NAME="Image36" TYPE="TEXT" />
  </METADATA>

  <RESULTSET FOUND="">
   <xsl:for-each select="propertys/property">
      <ROW RECORDID="" MODID="">

        <!-- REF -->
        <COL><DATA><xsl:value-of select="ref"/></DATA></COL>

        <!-- here I need to output 36 rows whether the property has 36 photos or not to match the Filemaker definition -->
        <COL><DATA></DATA></ROW> <!-- IMAGE 1 -->
        <COL><DATA></DATA></ROW> <!-- IMAGE 2 -->
        .... etc
     </ROW>
    </xsl:for-each>
  </RESULTSET>
</FMPXMLRESULT>

If anyone could help me understand this, it would be much appreciated.

Many thanks.