condition mean min max ZT0-3 1.842275 1.842275 1.842275 ZT4-7 1.50168 1.50168 1.50168 ZT8-11 3.037635 3.037635 3.037635 ZT12-15 1.98466 1.98466 1.98466 ZT16-19 2.04822 2.04822 2.04822 ZT20-23 1.807775 1.807775 1.807775