condition mean min max ZT0-3 5.550000000000001 5.550000000000001 5.550000000000001 ZT4-7 4.8 4.8 4.8 ZT8-11 12.25 12.25 12.25 ZT12-15 5.3999999999999995 5.3999999999999995 5.3999999999999995 ZT16-19 6.1 6.1 6.1 ZT20-23 9.55 9.55 9.55