condition mean min max ZT0-3 9.504811666666667 6.58953 11.341349999999998 ZT4-7 7.529835 7.529835 7.529835 ZT8-11 9.323799999999999 9.323799999999999 9.323799999999999 ZT12-15 12.5567 11.99365 13.11975 ZT16-19 11.36085 11.36085 11.36085 ZT20-23 14.20585 14.20585 14.20585