This is the Monetary Imbalance graph from yesterday's post. It uses numbers from Series X 410-419 of the Historical Statistics.
The blue trend-line goes up from 1915 until the Great Depression. Then it falls until the middle of World War II. Then it goes up again. By 1970 it is higher than when the Great Depression started. By 1970 we could have known trouble was on the way.
Below is the Monetary Imbalance graph, long-term. This graph uses the same Series X numbers for the blue 1915-1970 trends, and FRED numbers for the more recent red trendline, 1959-2010. I have made this graph an odd size so that the blue 1915-1970 trend-line looks like the graph above.
Again for comparison: