condition mean min max ZT0-3 1.657835 1.470335 1.90064 ZT4-7 1.176175 1.176175 1.176175 ZT8-11 2.4299749999999998 2.4299749999999998 2.4299749999999998 ZT12-15 3.7001799999999996 3.6494299999999997 3.75093 ZT16-19 3.707865 3.707865 3.707865 ZT20-23 2.73753 2.73753 2.73753