condition mean min max ZT0-3 10.008208 10.008208 10.008208 ZT4-7 10.1398835 10.1398835 10.1398835 ZT8-11 9.5183355 9.5183355 9.5183355 ZT12-15 9.278159 9.278159 9.278159 ZT16-19 9.468722 9.468722 9.468722 ZT20-23 9.26967 9.26967 9.26967