Procure inflation and population time-series data

[slightlyoff]

It'd be good if there were a way to show inflation-adjusted values for spending/revenue in terms of inflation-adjusted dollars (not nominal dollars) as well as on a per-capita basis. Inflation and population data for SF for the last 25 years would be key to enabling this.

[slightlyoff]

Done, but can't commit. Hoping @hannahyoung can add me as a collaborator to resolve.