condition mean min max ZT0-3 16.394333 16.394333 16.394333 ZT4-7 16.3255585 16.3255585 16.3255585 ZT8-11 17.7284905 17.7284905 17.7284905 ZT12-15 15.457656 15.457656 15.457656 ZT16-19 14.860806499999999 14.860806499999999 14.860806499999999 ZT20-23 16.332321999999998 16.332321999999998 16.332321999999998