condition mean min max ZT0-3 9.01263175875 7.750976677000001 10.2742868405 ZT4-7 7.25054910325 5.3498686195000005 9.151229587 ZT8-11 2.9704065877500003 2.093353854 3.8474593215000006 ZT12-15 19.536871714 15.771134403000001 23.302609025000002 ZT16-19 39.0261728925 35.260251225000005 42.79209456 ZT20-23 50.943859555 49.885412535 52.002306575