condition mean min max ZT0-3 6.6368425 6.427575 6.8461099999999995 ZT4-7 2.709675 2.709675 2.709675 ZT8-11 3.474235 3.474235 3.474235 ZT12-15 0 0 0 ZT16-19 5.564185 5.564185 5.564185 ZT20-23 6.761375 6.761375 6.761375