<simpleType name="StatisticEnumType">
  <restriction base="string">
    <enumeration value="individual">
      <annotation>
        <documentation>The criterion is evaluated against each measurement in its scope separately, with no reduction to a single value.</documentation>
      </annotation>
    </enumeration>
    <enumeration value="mean">
      <annotation>
        <documentation>The criterion is evaluated against the arithmetic mean of the measurements in its scope.</documentation>
      </annotation>
    </enumeration>
    <enumeration value="median">
      <annotation>
        <documentation>The criterion is evaluated against the median of the measurements in its scope.</documentation>
      </annotation>
    </enumeration>
    <enumeration value="minimum">
      <annotation>
        <documentation>The criterion is evaluated against the smallest of the measurements in its scope.</documentation>
      </annotation>
    </enumeration>
    <enumeration value="maximum">
      <annotation>
        <documentation>The criterion is evaluated against the largest of the measurements in its scope.</documentation>
      </annotation>
    </enumeration>
    <enumeration value="percentile">
      <annotation>
        <documentation>The criterion is evaluated against a stated percentile of the measurements in its scope; the percentile intended is given by the sibling percentileValue element.</documentation>
      </annotation>
    </enumeration>
    <enumeration value="standard deviation">
      <annotation>
        <documentation>The criterion is evaluated against the standard deviation of the measurements in its scope.</documentation>
      </annotation>
    </enumeration>
    <enumeration value="coefficient of variation">
      <annotation>
        <documentation>The criterion is evaluated against the coefficient of variation (standard deviation divided by the mean) of the measurements in its scope, as a limit on scatter.</documentation>
      </annotation>
    </enumeration>
  </restriction>
</simpleType>