condition mean min max ZT0-3 43.099999999999994 43.099999999999994 43.099999999999994 ZT4-7 7.2 7.2 7.2 ZT8-11 23.0 23.0 23.0 ZT12-15 35.7 35.7 35.7 ZT16-19 18.15 18.15 18.15 ZT20-23 24.950000000000003 24.950000000000003 24.950000000000003