condition mean min max ZT0-3 21.7 21.7 21.7 ZT4-7 3.5 3.5 3.5 ZT8-11 5.199999999999999 5.199999999999999 5.199999999999999 ZT12-15 3.1500000000000004 3.1500000000000004 3.1500000000000004 ZT16-19 38.45 38.45 38.45 ZT20-23 8.55 8.55 8.55