condition mean min max ZT0-3 2.76365 2.76365 2.76365 ZT4-7 1.06898 1.06898 1.06898 ZT8-11 1.925955 1.925955 1.925955 ZT12-15 2.150525 2.150525 2.150525 ZT16-19 3.568135 3.568135 3.568135 ZT20-23 3.070685 3.070685 3.070685