condition mean min max ZT0-3 308.141361 308.141361 308.141361 ZT4-7 267.0968895 267.0968895 267.0968895 ZT8-11 279.471129 279.471129 279.471129 ZT12-15 259.385903 259.385903 259.385903 ZT16-19 245.1523325 245.1523325 245.1523325 ZT20-23 225.5176055 225.5176055 225.5176055