condition mean min max ZT0-3 5.35 5.35 5.35 ZT4-7 9.2 9.2 9.2 ZT8-11 37.1 37.1 37.1 ZT12-15 8.600000000000001 8.600000000000001 8.600000000000001 ZT16-19 12.0 12.0 12.0 ZT20-23 16.25 16.25 16.25