condition mean min max ZT0-3 20.472725 17.314700000000002 23.63075 ZT4-7 8.129325 8.129325 8.129325 ZT8-11 18.332250000000002 18.332250000000002 18.332250000000002 ZT12-15 0 0 0 ZT16-19 32.0489 32.0489 32.0489 ZT20-23 25.0257 25.0257 25.0257