condition mean min max ZT0-3 572.385903 572.385903 572.385903 ZT4-7 1135.018969 1135.018969 1135.018969 ZT8-11 1089.4081655 1089.4081655 1089.4081655 ZT12-15 844.0679685 844.0679685 844.0679685 ZT16-19 660.5873165 660.5873165 660.5873165 ZT20-23 481.300075 481.300075 481.300075