condition mean min max ZT0-3 21.3 21.3 21.3 ZT4-7 39.7 39.7 39.7 ZT8-11 22.150000000000002 22.150000000000002 22.150000000000002 ZT12-15 24.549999999999997 24.549999999999997 24.549999999999997 ZT16-19 30.2 30.2 30.2 ZT20-23 33.8 33.8 33.8