condition mean min max ZT0-3 6.75 6.75 6.75 ZT4-7 45.0 45.0 45.0 ZT8-11 21.950000000000003 21.950000000000003 21.950000000000003 ZT12-15 26.65 26.65 26.65 ZT16-19 15.5 15.5 15.5 ZT20-23 11.649999999999999 11.649999999999999 11.649999999999999