condition mean min max ZT0-3 31.232649 31.232649 31.232649 ZT4-7 41.553772 41.553772 41.553772 ZT8-11 28.981481000000002 28.981481000000002 28.981481000000002 ZT12-15 40.363111 40.363111 40.363111 ZT16-19 25.141863999999998 25.141863999999998 25.141863999999998 ZT20-23 23.400317 23.400317 23.400317