condition mean min max ZT0-3 33.96953 33.96953 33.96953 ZT4-7 21.86655 21.86655 21.86655 ZT8-11 18.545841000000003 18.545841000000003 18.545841000000003 ZT12-15 20.7181585 20.7181585 20.7181585 ZT16-19 18.3719015 18.3719015 18.3719015 ZT20-23 20.244204500000002 20.244204500000002 20.244204500000002