condition mean min max ZT0-3 2.0 2.0 2.0 ZT4-7 0.7 0.7 0.7 ZT8-11 1.15 1.15 1.15 ZT12-15 11.25 11.25 11.25 ZT16-19 6.6000000000000005 6.6000000000000005 6.6000000000000005 ZT20-23 1.9 1.9 1.9