condition mean min max ZT0-3 6.19796 6.19796 6.19796 ZT4-7 3.652365 3.652365 3.652365 ZT8-11 4.713125 4.713125 4.713125 ZT12-15 6.530765000000001 6.530765000000001 6.530765000000001 ZT16-19 7.779755 7.779755 7.779755 ZT20-23 7.776915 7.776915 7.776915