condition mean min max ZT0-3 16.81105 16.81105 16.81105 ZT4-7 9.961535 9.961535 9.961535 ZT8-11 13.94805 13.94805 13.94805 ZT12-15 16.13725 16.13725 16.13725 ZT16-19 24.8867 24.8867 24.8867 ZT20-23 21.09705 21.09705 21.09705