condition mean min max ZT0-3 25.556480902 19.604049914 31.50891189 ZT4-7 4.653888370000001 3.9203176235 5.3874591165000005 ZT8-11 2.91412134025 2.351517145 3.4767255355 ZT12-15 4.05544554075 3.6447253799999997 4.4661657015000005 ZT16-19 6.35713598425 4.983647507500001 7.730624461 ZT20-23 8.61809620725 8.584444337999999 8.6517480765