condition mean min max ZT0-3 10.55 10.55 10.55 ZT4-7 11.8 11.8 11.8 ZT8-11 11.950000000000001 11.950000000000001 11.950000000000001 ZT12-15 8.9 8.9 8.9 ZT16-19 4.0 4.0 4.0 ZT20-23 12.4 12.4 12.4