Can anyone help verify if these queries will work? Don't have access to system to verify and trying to help other Koha users complete these questions on the PLDS Annual Survey. /* calculate annual average days of circulation of items by item type */ SELECT r.itemtype, sum(r.datetime-b.datetime)/count(r.datetime) as *avg_days_of_circ* FROM statistics r, statistics b WHERE r.type='return' and b.type='issue' AND r.itemnumber=b.itemnumber AND r.borrowernumber=b.borrowernumber AND year(r.datetime)=2017 GROUP BY r.itemtype; /* the number of original circulations (not including renewals) by item type */ SELECT itemtype, count(*) as *intitial_circ* FROM statistics WHERE type='issue' AND year(datetime)=2017 GROUP BY itemtype; /* the number of renewals by item type */ SELECT itemtype, count(*) as *renewals* FROM statistics WHERE type='renewal' AND year(datetime)=2017 GROUP BY itemtype; Thanks! -- Carl Thompson <cthompson@countingopinions.com> Counting Opinions <http://www.countingopinions.com/> (866) 994-0904 <+18669940904>