Between 11% and 18% of injured workers in 15 states do not return to work within a year of their accident, a range that is in line with previous studies, according to reports released Tuesday by the Workers Compensation Research Institute. The Cambridge, Massachusetts-based institute released its latest batch of reports tackling data in six new states - Indiana, Massachusetts, Michigan, North Carolina, Virginia, and Wisconsin -and found that recovery of physical health and functioning for injured workers was similar across the 15 states researched over the last few years.