condition mean min max ZT0-3 0.5000163333333333 0.0838025 1.330215 ZT4-7 1.429526 1.429526 1.429526 ZT8-11 2.76389 2.76389 2.76389 ZT12-15 2.2087475000000003 1.4331049999999999 2.9843900000000003 ZT16-19 0.4893645 0.4893645 0.4893645 ZT20-23 0.282776 0.282776 0.282776