condition mean min max ZT0-3 155.385903 155.385903 155.385903 ZT4-7 138.543454 138.543454 138.543454 ZT8-11 150.225738 150.225738 150.225738 ZT12-15 145.588603 145.588603 145.588603 ZT16-19 170.697949 170.697949 170.697949 ZT20-23 187.352947 187.352947 187.352947