condition mean min max ZT0-3 15.495566666666667 15.086500000000001 16.1451 ZT4-7 22.67125 22.67125 22.67125 ZT8-11 21.61655 21.61655 21.61655 ZT12-15 21.762674999999998 19.244149999999998 24.2812 ZT16-19 20.6002 20.6002 20.6002 ZT20-23 17.874850000000002 17.874850000000002 17.874850000000002