condition mean min max ZT0-3 14.0 14.0 14.0 ZT4-7 20.9 20.9 20.9 ZT8-11 15.450000000000001 15.450000000000001 15.450000000000001 ZT12-15 15.700000000000001 15.700000000000001 15.700000000000001 ZT16-19 9.25 9.25 9.25 ZT20-23 19.85 19.85 19.85