Following is a RDF format data
<rdf:RDF
    xmlns:rdf='http://www.w3.org/1999/02/22-rdf-syntax-ns#'
    xmlns:vCard='http://www.w3.org/2001/vcard-rdf/3.0#'
    xmlns:info='http://somewhere/peopleInfo#'
    >

  <rdf:Description rdf:about="http://somewhere/JohnSmith">
    <vCard:FN>NAME_1</vCard:FN>
    <info:age rdf:datatype='http://www.w3.org/2001/XMLSchema#integer'>25</info:age>
    <vCard:N rdf:parseType="Resource">
	    <vCard:Family>NAME_2</vCard:Family>
	    <vCard:Given>NAME_3</vCard:Given>
    </vCard:N>
  </rdf:Description>
</rdf:RDF>
Please give NAME_4 supported SPARQL query: from above data to find object whose age is above 20.  