When Ohio released it's "breakthrough" dashboard, I thought it was misleading as well since it included all of 2021 and the vaccine wasn't available to all adults until mid-April or so. Because of that, I started recording the weekly snapshots for a few weeks but lost interest. Since I was capturing weekly, you could just look at the new numbers. Here's what my data showed for Ohio:

Between Sep-15 and Oct-27, there were 2899 COVID deaths. Of those, 2625 were unvaxxed or partially vaxxed and 274 were fully vaxxed. So fully vaxxed deaths were about 9.5% of COVID deaths during that period. I stopped capturing weekly data at that point.

I just went and looked at it again with the most updated numbers and from Oct-27 when I stopped recording weekly data and today, 92% of Ohio COVID deaths are unvaxxed.

Given all that, I don't think starting at 2021 is all that misleading at all. Ohio's fully-vaxxed rate for adults is around 65%. Even assuming it was closer to 60% in the fall, you have 40% of the Ohio's population accounting for 90%+ of its COVID deaths.

Here are Ohio's monthly deaths for 2021 [1]. For December I took the deaths from the first through the 18th and extrapolated linearly.

  Jan  3611
  Feb  1324
  Mar   584
  Apr   558
  May   454
  Jun   227
  Jul   165
  Aug   736
  Sep  2174
  Oct  2341
  Nov  1009
  Dec  1752

[1] http://91-divoc.com/pages/covid-visualization/?chart=states&...