condition mean min max ZT0-3 13.200000000000001 13.200000000000001 13.200000000000001 ZT4-7 69.0 69.0 69.0 ZT8-11 78.9 78.9 78.9 ZT12-15 94.5 94.5 94.5 ZT16-19 59.199999999999996 59.199999999999996 59.199999999999996 ZT20-23 20.75 20.75 20.75