condition mean min max ZT0-3 11.6 11.6 11.6 ZT4-7 4.4 4.4 4.4 ZT8-11 18.3 18.3 18.3 ZT12-15 16.2 16.2 16.2 ZT16-19 8.7 8.7 8.7 ZT20-23 13.950000000000001 13.950000000000001 13.950000000000001