condition mean min max ZT0-3 1.8063433333333332 1.1858499999999998 2.7935749999999997 ZT4-7 2.6030300000000004 2.6030300000000004 2.6030300000000004 ZT8-11 3.940255 3.940255 3.940255 ZT12-15 4.440485 4.3463899999999995 4.53458 ZT16-19 3.50063 3.50063 3.50063 ZT20-23 2.78425 2.78425 2.78425