condition mean min max ZT0-3 8.838625 8.838625 8.838625 ZT4-7 5.4269549999999995 5.4269549999999995 5.4269549999999995 ZT8-11 6.47199 6.47199 6.47199 ZT12-15 10.742115 10.742115 10.742115 ZT16-19 11.37065 11.37065 11.37065 ZT20-23 9.803405000000001 9.803405000000001 9.803405000000001