condition mean min max ZT0-3 20.85 20.85 20.85 ZT4-7 30.2 30.2 30.2 ZT8-11 16.05 16.05 16.05 ZT12-15 11.450000000000001 11.450000000000001 11.450000000000001 ZT16-19 19.2 19.2 19.2 ZT20-23 14.950000000000001 14.950000000000001 14.950000000000001