Here is a graph of expenditures on energy goods and services as a percent of total personal consumption expenditures through December 2014.
This is one of the measures that Professor Hamilton at Econbrowser looks at to evaluate any drag on GDP from energy prices.
Click on graph for larger image.
Data source: BEA Table 2.3.5U.
The huge spikes in energy prices during the oil crisis of 1973 and 1979 are obvious. As is the increase in energy prices during the 2001 through 2008 period.
With the recent decline in energy prices, this ratio has declined sharply. Hopefully energy prices are resuming their long term down trend as a percent of PCE.