condition mean min max ZT0-3 6.1112375 5.242595 6.97988 ZT4-7 3.49534 3.49534 3.49534 ZT8-11 6.689755 6.689755 6.689755 ZT12-15 0 0 0 ZT16-19 6.0055250000000004 6.0055250000000004 6.0055250000000004 ZT20-23 6.29775 6.29775 6.29775