condition mean min max ZT0-3 8.3 8.3 8.3 ZT4-7 2.4 2.4 2.4 ZT8-11 4.550000000000001 4.550000000000001 4.550000000000001 ZT12-15 7.15 7.15 7.15 ZT16-19 4.2 4.2 4.2 ZT20-23 4.85 4.85 4.85