condition mean min max ZT0-3 7.947303333333333 7.1111 8.842875 ZT4-7 6.51726 6.51726 6.51726 ZT8-11 18.0943 18.0943 18.0943 ZT12-15 16.01515 11.19275 20.83755 ZT16-19 9.863109999999999 9.863109999999999 9.863109999999999 ZT20-23 11.452649999999998 11.452649999999998 11.452649999999998