condition mean min max ZT0-3 18.360475 15.73685 20.984099999999998 ZT4-7 20.049599999999998 20.049599999999998 20.049599999999998 ZT8-11 6.74348 6.74348 6.74348 ZT12-15 0 0 0 ZT16-19 5.49836 5.49836 5.49836 ZT20-23 21.43555 21.43555 21.43555