condition mean min max ZT0-3 2.3 2.3 2.3 ZT4-7 1.1 1.1 1.1 ZT8-11 9.75 9.75 9.75 ZT12-15 1.7000000000000002 1.7000000000000002 1.7000000000000002 ZT16-19 3.5 3.5 3.5 ZT20-23 2.6 2.6 2.6