condition mean min max ZT0-3 21.7 21.7 21.7 ZT4-7 6.7 6.7 6.7 ZT8-11 4.3 4.3 4.3 ZT12-15 25.450000000000003 25.450000000000003 25.450000000000003 ZT16-19 1.65 1.65 1.65 ZT20-23 18.9 18.9 18.9