The required n attribute is the number of values in the list.
Source
<xs:element name="Values" type="SubgroupIntegerArrayType"><xs:annotation><xs:documentation>The Values element is the array of integer values associated with subgroup ids.</xs:documentation></xs:annotation></xs:element>
The SubgroupIntegersType defines a list of SubgroupIntegerType and optionally defines the software, standard or specification, or algorithm to be used to determine the list of integers.
<xs:complexType name="SubgroupIntegersType"><xs:annotation><xs:documentation>The SubgroupIntegersType defines a list of SubgroupIntegerType and optionally defines the software, standard or specification, or algorithm to be used to determine the list of integers.</xs:documentation></xs:annotation><xs:complexContent><xs:extension base="StatsWithReferenceBaseType"><xs:sequence><xs:element name="Values" type="SubgroupIntegerArrayType"><xs:annotation><xs:documentation>The Values element is the array of integer values associated with subgroup ids.</xs:documentation></xs:annotation></xs:element></xs:sequence></xs:extension></xs:complexContent></xs:complexType>