condition mean min max ZT0-3 0.864947 0.864947 0.864947 ZT4-7 0.682331 0.682331 0.682331 ZT8-11 0.4638645 0.4638645 0.4638645 ZT12-15 0.8687165 0.8687165 0.8687165 ZT16-19 1.25017 1.25017 1.25017 ZT20-23 1.216995 1.216995 1.216995