Thanks for taking the time to help me out. You're right -- inflation is a difficult problem to solve and does need to be taken into account.
I tried to get a handle on inflation using the stats.pct_dev column, which is the ratio of the stddev to the avg Dow for the year.
The idea is that I could sort based on the percentage stddev/avg, and that would show me years with the highest proportional volatility. So a 100-point swing in 1920 would have been disastrous, and would rank very highly, but a 100-point swing in 2008 would be toward the bottom of the list -- occurring almost daily.
That doesn't totally deal with the inflation problem, but it does help to put the numbers in better perspective. I have another query that I didn't post -- essentially the same, but where I ran the numbers grouped by month. I wrote about the results of that query when I was talking about how the different months rank with history. In this query, I don't think inflation would be much of an issue.
Either way, the effect of inflation on the rankings should be fairly well contained, because percentage change, stddev, and pct_dev (stddev/avg) were all calculated on yearly or monthly basis. The % change between years was only ever compared between consecutive years, and there could definitely be some inflationary skew there, but I'm thinking it's also generally pretty reasonable and doesn't make the comparison unfair.