condition mean min max ZT0-3 1.9162625 1.64467 2.187855 ZT4-7 6.275980000000001 6.275980000000001 6.275980000000001 ZT8-11 1.8331849999999998 1.8331849999999998 1.8331849999999998 ZT12-15 0 0 0 ZT16-19 2.251605 2.251605 2.251605 ZT20-23 2.51053 2.51053 2.51053