condition mean min max ZT0-3 6.4131725 5.849465 6.9768799999999995 ZT4-7 7.776115000000001 7.776115000000001 7.776115000000001 ZT8-11 4.170535 4.170535 4.170535 ZT12-15 0 0 0 ZT16-19 6.477304999999999 6.477304999999999 6.477304999999999 ZT20-23 5.348435 5.348435 5.348435