Running same events in 2008 vs. 2012 data

I work from an economic development agency and a company we are trying to attract to the region was asked by NYS to create an economic impact analysis of their project. At the time of the request we told them we only had 2008 data and that 2012 was around the corner, but they requested we at least run it with what we had. We did and then we secured the 2012 data and there was a big drop in the results. I attributed this to a shrunken supply chain in NYS as a result of the recession as well as what appears to be a diminished output per worker for the sector. They were satisfied with that answer but they also wanted me to run it past MIG to see if there was anything I was missing that would account for the drop. The scenario was an impact using NYS as the geography and sector 209 as the industry. The only input we entered was employment, 110. I zeroed out the proprietor income as well. Were my assumptions accurate or are there better explanations for the decline that can be offered? i think they have concerns that somehow the underlying data might be incorrect, but I felt confident that wasn't the issue.