Author: Shamim Rezaie
MDL-63186 quiz_statistics: Show each columns min,max in the summary row
The statistics table have been modified so that the summary row shows the minimum and maximum
values of each column for the set of questions that are being summarised.
Part of MDL-62610
http://git.moodle.org/gw?p=moodle.git;a=commit;h=666889f0f81d5b7bca351ab6847e92b471db92bf
http://github.com/moodle/moodle/commit/666889f0f81d5b7bca351ab6847e92b471db92bf
+ 3.6 en [rangebetween,quiz_statistics]