Author: James Pratt
MDL-41757 quiz statistics : limit subq and variant stat rows
and print min, median and max.
http://git.moodle.org/gw?p=moodle.git;a=commit;h=df9ddae6866b77b2884cbf69a093ffe90bb8068d
http://github.com/moodle/moodle/commit/df9ddae6866b77b2884cbf69a093ffe90bb8068d
+ 2.7 en [maximumfacility,quiz_statistics]
+ 2.7 en [medianfacility,quiz_statistics]
+ 2.7 en [minimumfacility,quiz_statistics]