condition mean min max ZT0-3 5.38857 3.02294 7.1013649999999995 ZT4-7 3.537185 3.537185 3.537185 ZT8-11 8.13578 8.13578 8.13578 ZT12-15 7.62548 6.848195 8.402765 ZT16-19 6.385975 6.385975 6.385975 ZT20-23 7.910584999999999 7.910584999999999 7.910584999999999