condition mean min max ZT0-3 12.4 12.4 12.4 ZT4-7 6.3 6.3 6.3 ZT8-11 13.7 13.7 13.7 ZT12-15 19.35 19.35 19.35 ZT16-19 15.95 15.95 15.95 ZT20-23 7.300000000000001 7.300000000000001 7.300000000000001