Michigan: *Final* avg. unsubsidized 2020 #ACA premium rate changes: 2.1% decrease no matter what DIFS says

Back in August, I posted an analysis of the preliminary 2020 premium rate filings for the ACA Individual Market here in Michigan based on the actual filing forms from each of the 11 carriers participating in the market.

At the time, I concluded that the weighted average change marketwide was a 2.1% reduction in premiums compared to 2019, for around 333,000 Michiganders on the Indy market. This would mean roughly a $10 average premium reduction per unsubsidized enrollee per month, or $122 per year:

The Michigan Dept. of Insurance & Financial Services issued a press release and the following report, which includes the official (still preliminary) 2020 rate filings for both the Individual and Small Group markets (click the image for a higher-res version):

They later corrected their typo to add a negative sign in front of the 2.5% average at the bottom, as Louise Norris called to my attention:

However, they're still off by a bit. With the final, approved 2020 rate changes being posted by CMS today, here's what Michigan's landscape looks like for unsubsidized average premiums:

MI DIFS says it's a 2.5% average reduction, but the hard enrollment numbers and final rate changes put it at 2.1%. Not a huge gap, but still a bit puzzling.