'
States with no
shading (white) are non-participants in the OSHA BLS Survey.
Tier I
- Average grade of A (or B+ or better) and a trend going up or level
Tier II - Average grade
of A (or B+ or better) and a trend going down
Tier III - Average grade
between B & D and a trend going up or level
Tier IV - Average
grade between B & D and a trend going down
Tier V - Average
grade of F (or D- or worse) and a trend going up
Tier VI - Average
grade of F (or D- or worse) and a trend down or level