condition mean min max ZT0-3 3.6495033333333335 2.29197 5.543290000000001 ZT4-7 6.0259350000000005 6.0259350000000005 6.0259350000000005 ZT8-11 6.648765 6.648765 6.648765 ZT12-15 5.270545 3.99505 6.54604 ZT16-19 3.1594550000000003 3.1594550000000003 3.1594550000000003 ZT20-23 4.0765899999999995 4.0765899999999995 4.0765899999999995