condition mean min max ZT0-3 4.550000000000001 4.550000000000001 4.550000000000001 ZT4-7 47.4 47.4 47.4 ZT8-11 7.3999999999999995 7.3999999999999995 7.3999999999999995 ZT12-15 12.1 12.1 12.1 ZT16-19 14.5 14.5 14.5 ZT20-23 19.7 19.7 19.7