http://science.energy.gov/~/media/hep/hepap/pdf/201403/Rolli...
The DOE HEP Theory budget has supposedly been dropping since 2014 -- actually 2012:
http://www.math.columbia.edu/~woit/wordpress/?p=8998
I suspect the amount of time spent on writing grants and informal fund raising is related to the level of competition, how many theorists are pursuing how little money rather than the absolute amount of money available.
The National Institutes of Health (NIH) has many billions, but the probability of getting a grant is very low due to the huge overproduction of biology Ph.D.'s consequently researchers and would be researchers spend enormous amounts of time writing grant proposals, most of which are turned down.
https://nexus.od.nih.gov/all/2015/06/29/what-are-the-chances...
The success/award rates in the above article (about 18 percent) actually seem high. I have seen numbers as low as 9 percent in some articles.
Modern physics has very few long term secure jobs to think about actual physics. Tenured faculty spend most of their time writing grant applications and fund raising -- not the same thing.