condition mean min max ZT0-3 2.1 2.1 2.1 ZT4-7 1.3 1.3 1.3 ZT8-11 7.0 7.0 7.0 ZT12-15 1.25 1.25 1.25 ZT16-19 1.2000000000000002 1.2000000000000002 1.2000000000000002 ZT20-23 1.5499999999999998 1.5499999999999998 1.5499999999999998