condition mean min max ZT0-3 20.099999999999998 20.099999999999998 20.099999999999998 ZT4-7 7.4 7.4 7.4 ZT8-11 10.9 10.9 10.9 ZT12-15 10.850000000000001 10.850000000000001 10.850000000000001 ZT16-19 5.25 5.25 5.25 ZT20-23 9.899999999999999 9.899999999999999 9.899999999999999