condition mean min max ZT0-3 32.85 32.85 32.85 ZT4-7 3.2 3.2 3.2 ZT8-11 21.6 21.6 21.6 ZT12-15 5.800000000000001 5.800000000000001 5.800000000000001 ZT16-19 17.4 17.4 17.4 ZT20-23 13.9 13.9 13.9