condition mean min max ZT0-3 37.900000000000006 37.900000000000006 37.900000000000006 ZT4-7 7.3 7.3 7.3 ZT8-11 40.8 40.8 40.8 ZT12-15 16.099999999999998 16.099999999999998 16.099999999999998 ZT16-19 30.0 30.0 30.0 ZT20-23 70.65 70.65 70.65