Two years after lawmakers tightened eligibility for benefits to injured workers, the insurance premiums businesses must pay to care for injured workers have dropped to 1994 levels.

In 2005, Gov. Matt Blunt and the Republican-led Legislature limited what kinds of injuries are eligible for benefits through the state workers' compensation system. Those changes included requiring workers prove that their jobs were the primary cause of their injury. The law also cut benefits when workers have drugs or alcohol in their system.

State law requires most employers to have workers' compensation insurance. Data from the state insurance department show employer payments for workers' compensation insurance have dropped almost 3 percent from the start of 2007 to the end of April.