condition mean min max ZT0-3 0.7501351666666667 0.401258 1.1140705 ZT4-7 0.587796 0.587796 0.587796 ZT8-11 0.6976545000000001 0.6976545000000001 0.6976545000000001 ZT12-15 1.2440925 1.2245300000000001 1.263655 ZT16-19 1.211065 1.211065 1.211065 ZT20-23 1.1946725 1.1946725 1.1946725