condition mean min max ZT0-3 1.9242875000000002 1.7925550000000001 2.05602 ZT4-7 1.4033 1.4033 1.4033 ZT8-11 1.66085 1.66085 1.66085 ZT12-15 0 0 0 ZT16-19 2.503265 2.503265 2.503265 ZT20-23 2.37161 2.37161 2.37161