condition mean min max ZT0-3 6.5887075 6.231695 6.94572 ZT4-7 5.47549 5.47549 5.47549 ZT8-11 6.755735 6.755735 6.755735 ZT12-15 0 0 0 ZT16-19 8.088035 8.088035 8.088035 ZT20-23 7.855115 7.855115 7.855115