Table 1 Years of exposure weighted by probability and intensity equivalent to 1 year of cumulative exposure*
ProbabilityIntensityDuration
LowMediumHigh
Assigned weightsYears of exposure
10–50%Low0.33.5
50–90%Medium0.50.72.01.5
>90%High0.71.01.01.51.01.0
  • *Assigned weight × years of exposure  =  cumulative exposure.