The Experience Modification Rate (EMR) was developed by the insurance industry as an equitable means of determining premiums for Workers Compensation insurance. 

EMR's can show a contractor's trend in safety performance by comparing a business' specific payrolls and losses to the industry averages in the same industry.

An EMR of 1.0 means that a business is at its industry average.
If the business' experience is 20% better than average, the EMR would be a 0.80.
If the experience is 20% worse, the EMR would be a 1.20.