condition mean min max ZT0-3 1.7 1.7 1.7 ZT4-7 1.4 1.4 1.4 ZT8-11 22.700000000000003 22.700000000000003 22.700000000000003 ZT12-15 2.2 2.2 2.2 ZT16-19 3.7 3.7 3.7 ZT20-23 2.6 2.6 2.6