condition mean min max ZT0-3 1.2118766666666667 1.107005 1.29577 ZT4-7 1.2037550000000001 1.2037550000000001 1.2037550000000001 ZT8-11 0.7119420000000001 0.7119420000000001 0.7119420000000001 ZT12-15 1.24762325 1.0297465 1.4655 ZT16-19 1.1851099999999999 1.1851099999999999 1.1851099999999999 ZT20-23 1.885005 1.885005 1.885005