condition mean min max ZT0-3 9.35 9.35 9.35 ZT4-7 5.7 5.7 5.7 ZT8-11 7.199999999999999 7.199999999999999 7.199999999999999 ZT12-15 8.5 8.5 8.5 ZT16-19 3.6 3.6 3.6 ZT20-23 4.5 4.5 4.5