condition mean min max ZT0-3 6.2 6.2 6.2 ZT4-7 8.1 8.1 8.1 ZT8-11 36.45 36.45 36.45 ZT12-15 16.75 16.75 16.75 ZT16-19 59.9 59.9 59.9 ZT20-23 57.75 57.75 57.75