condition mean min max ZT0-3 10.718678333333335 8.092735000000001 12.68335 ZT4-7 9.022044999999999 9.022044999999999 9.022044999999999 ZT8-11 11.22645 11.22645 11.22645 ZT12-15 31.5181 30.951299999999996 32.084900000000005 ZT16-19 23.5137 23.5137 23.5137 ZT20-23 19.7157 19.7157 19.7157