condition mean min max ZT0-3 1.1925569999999999 1.1925569999999999 1.1925569999999999 ZT4-7 1.230021 1.230021 1.230021 ZT8-11 1.4886249999999999 1.4886249999999999 1.4886249999999999 ZT12-15 0.924322 0.924322 0.924322 ZT16-19 1.41734 1.41734 1.41734 ZT20-23 0.46412966666666666 0.46412966666666666 0.46412966666666666