condition mean min max ZT0-3 2.5229725000000003 2.3306500000000003 2.7152950000000002 ZT4-7 4.679185 4.679185 4.679185 ZT8-11 6.09828 6.09828 6.09828 ZT12-15 0 0 0 ZT16-19 7.079245 7.079245 7.079245 ZT20-23 4.1649 4.1649 4.1649