condition mean min max ZT0-3 1.1548796666666667 1.1548796666666667 1.1548796666666667 ZT4-7 1.154688 1.154688 1.154688 ZT8-11 0.82251 0.82251 0.82251 ZT12-15 1.52168 1.52168 1.52168 ZT16-19 1.2796509999999999 1.2796509999999999 1.2796509999999999 ZT20-23 0.6800660000000001 0.6800660000000001 0.6800660000000001