I appreciated this post, since it identified a genuine problem with my analysis: the government spending growth rates in different eras may largely be a result of inflation, rather than real growth, or population growth (when the more relevant question, for purposes of this analysis, is relative growth, which shows how big the government is relative to the population it is serving). So, I was happy to recrunch the numbers.
Most of the data was already in the link I already provided, which indicated population. However, I also had to use this link, for inflation index:
http://www.usinflationcalculator.com/inflation/consumer-price-index-and-annual-percent-changes-from-1913-to-2008/
Using that method, comparing 2013 to 2001 (a twelve-year change), total government spending growth was 2.511%, after adjusting for both population growth and inflation. In the prior 70 years, the average was 5.420%. So, using this new method, the answer is still the same: in the last twelve years, government spending growth has been well below half of the normal rate.
If you compare to the period with the best run of prosperity increase and excellent economic performance, from when the New Deal was under way, in 1934, through the end of the Johnson administration, in 1968, the numbers are even more interesting. During those 35 years of Democratic domination (Democratic presidents for 27 out of 35 years, mostly Democratic control over both houses of Congress, and a liberal Supreme Court), government grew by an inflation-and-population-adjusted 5.587% annualized, even as poverty and unemployment plummeted, incomes for most Americans soared, and the American Dream became a reality for most people.