condition mean min max ZT0-3 16.089866666666666 11.036999999999999 19.088749999999997 ZT4-7 10.16931 10.16931 10.16931 ZT8-11 10.449100000000001 10.449100000000001 10.449100000000001 ZT12-15 13.272575 12.29765 14.247499999999999 ZT16-19 13.542349999999999 13.542349999999999 13.542349999999999 ZT20-23 20.1644 20.1644 20.1644