condition mean min max ZT0-3 7.158526666666667 5.396145000000001 8.27695 ZT4-7 6.811845 6.811845 6.811845 ZT8-11 5.5586400000000005 5.5586400000000005 5.5586400000000005 ZT12-15 7.208855 6.720454999999999 7.697255 ZT16-19 6.883215 6.883215 6.883215 ZT20-23 8.3836 8.3836 8.3836