condition mean min max ZT0-3 24.948743 24.948743 24.948743 ZT4-7 17.5679535 17.5679535 17.5679535 ZT8-11 16.4367105 16.4367105 16.4367105 ZT12-15 15.695014 15.695014 15.695014 ZT16-19 14.1896035 14.1896035 14.1896035 ZT20-23 14.3736005 14.3736005 14.3736005