condition mean min max ZT0-3 204.385903 204.385903 204.385903 ZT4-7 271.94265099999996 271.94265099999996 271.94265099999996 ZT8-11 353.38132399999995 353.38132399999995 353.38132399999995 ZT12-15 308.49805549999996 308.49805549999996 308.49805549999996 ZT16-19 332.10479250000003 332.10479250000003 332.10479250000003 ZT20-23 268.6311415 268.6311415 268.6311415