condition mean min max ZT0-3 3.558135 3.1540150000000002 3.962255 ZT4-7 4.777324999999999 4.777324999999999 4.777324999999999 ZT8-11 6.57503 6.57503 6.57503 ZT12-15 0 0 0 ZT16-19 4.39654 4.39654 4.39654 ZT20-23 3.128765 3.128765 3.128765