condition mean min max ZT0-3 10.226364 10.226364 10.226364 ZT4-7 9.7595745 9.7595745 9.7595745 ZT8-11 9.3294605 9.3294605 9.3294605 ZT12-15 9.71535 9.71535 9.71535 ZT16-19 11.049368999999999 11.049368999999999 11.049368999999999 ZT20-23 10.526783 10.526783 10.526783