condition mean min max ZT0-3 15.879266666666666 14.628599999999999 16.64965 ZT4-7 13.1499 13.1499 13.1499 ZT8-11 13.718499999999999 13.718499999999999 13.718499999999999 ZT12-15 17.025425000000002 16.0148 18.036050000000003 ZT16-19 15.1801 15.1801 15.1801 ZT20-23 17.06335 17.06335 17.06335