condition mean min max ZT0-3 7.241111111 7.241111111 7.241111111 ZT4-7 10.3 10.3 10.3 ZT8-11 9.58111111 9.58111111 9.58111111 ZT12-15 11.341111111 11.341111111 11.341111111 ZT16-19 5.691111111 5.691111111 5.691111111 ZT20-23 5.034444444666667 5.034444444666667 5.034444444666667