condition mean min max ZT0-3 3.7123683333333335 2.89541 4.875165 ZT4-7 3.961365 3.961365 3.961365 ZT8-11 6.122925 6.122925 6.122925 ZT12-15 7.823759999999999 7.625964999999999 8.021555 ZT16-19 5.20506 5.20506 5.20506 ZT20-23 3.07146 3.07146 3.07146