condition mean min max ZT0-3 14.009881666666667 6.170445 19.47625 ZT4-7 4.70384 4.70384 4.70384 ZT8-11 7.77346 7.77346 7.77346 ZT12-15 14.130400000000002 13.5416 14.7192 ZT16-19 15.16915 15.16915 15.16915 ZT20-23 26.335250000000002 26.335250000000002 26.335250000000002