DITA-OT XSLT stylesheet performance optimization

normalized.xsl

<?xml version="1.0" encoding="utf-8"?>

<xsl:stylesheet version="2.0"
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  xmlns:xs="http://www.w3.org/2001/XMLSchema"
  exclude-result-prefixes="xs">

  <xsl:output method="text"/>

  <xsl:template match="/">
     <xsl:apply-templates select="//topic[contains(@class, ' concept/concept ')]/body[contains(@class, ' concept/conbody ')][last()]"/>
  </xsl:template>

  <xsl:template match="topic[contains(@class, ' concept/concept ')]/body[contains(@class, ' concept/conbody ')][last()]">
    <xsl:value-of
      select="count(preceding::table[contains(@class, ' topic/table ')]/title[contains(@class, ' topic/title ')]) +
              count(preceding::fig[contains(@class, ' topic/fig ')]/title[contains(@class, ' topic/title ')])"/>
  </xsl:template>

  <!-- Average execution time over last 25 runs: 1.456811s (1456.811488ms) -->

</xsl:stylesheet>

unnormalized.xsl

<?xml version="1.0" encoding="utf-8"?>

<xsl:stylesheet version="2.0"
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  xmlns:xs="http://www.w3.org/2001/XMLSchema"
  exclude-result-prefixes="xs">

  <xsl:output method="text"/>

  <xsl:template match="/">
     <xsl:apply-templates select="//*[contains(@class, ' concept/concept ')]/*[contains(@class, ' concept/conbody ')][last()]"/>
  </xsl:template>

  <xsl:template match="*[contains(@class, ' concept/concept ')]/*[contains(@class, ' concept/conbody ')][last()]">
    <xsl:value-of
      select="count(preceding::*[contains(@class, ' topic/table ')]/*[contains(@class, ' topic/title ')]) +
              count(preceding::*[contains(@class, ' topic/fig ')]/*[contains(@class, ' topic/title ')])"/>
  </xsl:template>

  <!-- *** Average execution time over last 25 runs: 3.231367s (3231.367094ms) -->

</xsl:stylesheet>