condition mean min max ZT0-3 2.579963945 2.519899862 2.6400280279999997 ZT4-7 2.079483652 1.8618881605 2.2970791435 ZT8-11 2.1768827 2.091845216 2.261920184 ZT12-15 2.435435863 1.9872626044999997 2.8836091215 ZT16-19 3.1853644105 2.5216300455000003 3.8490987755 ZT20-23 7.28828367825 6.2713200725 8.305247284