Data sets and methodology notes for the article, "The C Fund at 35: Trust the Long-Term Data When Investing in the TSP"
S&P 500 data is available on the official S&P site here. Go to "documents" -> "additional info" -> "index earnings" to download the .xlsx file.
Monthly TSP fund returns data is available on the official tsp.gov site under "Fund Performance," here.
The S&P 500 and monthly dividend figures were adapted from Case-Shiller's "U.S. Stock Markets 1871-Present and CAPE Ratio" data, available here.
Calculations, graphing, and methodology checks are detailed in the attached Jupyter Notebook.