condition mean min max ZT0-3 11.037605 9.838705000000001 12.236505 ZT4-7 8.212715 8.212715 8.212715 ZT8-11 7.9508849999999995 7.9508849999999995 7.9508849999999995 ZT12-15 0 0 0 ZT16-19 10.071325 10.071325 10.071325 ZT20-23 11.74035 11.74035 11.74035