How Much Lower Can the Market Go?

We all know (or we will soon find out!) what a math geek I am. I obtained the source data for the Dow Jones Industrial Average for the entire 20th century for data analysis. When I charted this data, it sort of scared me, because I don't know when we'll hit bottom.

The spike that has been occurring just doesn't seem to fit the pattern, and it worries me that in order to truly reset, we've still got to go down further.

I ran a regression analysis with the data from 1900 through 1984 (right before the spike really took off) and found that if the trend had continued on that path, we'd be at 1,176 today, but we're actually at 6,574, a number that is very low according to all reports.

Maybe the current market is too different from the pre-1990's market to make the comparison and we don't have anything to worry about; or maybe we still have some correction to do before we really reset. I'm not an economist, so I don't know which way this will go, it's just something that I'm wondering about and will keep watching.