condition mean min max ZT0-3 0.3684113333333333 0.3269305 0.424607 ZT4-7 2.646685 2.646685 2.646685 ZT8-11 0.48681450000000004 0.48681450000000004 0.48681450000000004 ZT12-15 1.34200225 0.3953595 2.288645 ZT16-19 1.254265 1.254265 1.254265 ZT20-23 0.994782 0.994782 0.994782