condition mean min max ZT0-3 1.14920625 1.1055220000000001 1.1928904999999999 ZT4-7 0.5018325 0.5018325 0.5018325 ZT8-11 1.4143400000000002 1.4143400000000002 1.4143400000000002 ZT12-15 0 0 0 ZT16-19 1.9774450000000001 1.9774450000000001 1.9774450000000001 ZT20-23 1.6877149999999999 1.6877149999999999 1.6877149999999999