[xwiki-users] XWQL query: Grouping Date properties by year ?

Hello, The following query counts documents by publication date. {{velocity}} ## Count all publication dates #set($results=$services.query.xwql("select guide.DocumentDate, count(guide.DocumentDate) from Document doc, doc.object(BIMGuides.GuideClass) as guide group by guide.DocumentDate order by guide.DocumentDate").execute()) PublicationDate,Count #foreach($result in $results) #set($resDate = $result.get(0)) #set($resString = $resDate.toString().substring(0, 10)) $resString,$result.get(1) #end {{/velocity}} I would like to regroup publication dates by year (getting « 2014,3 » when 2 documents are published in Jan2014 and 1 in Oct2014) instead of getting all single dates. Any idea ? Thank you in advance! Sylvain