feat(per-capita): use per-year F-33 population in spending verbs

cog_spending(per_capita = TRUE) and cog_revenue(per_capita = TRUE) now
divide each year's amount by that gov-year's population from
gov_population_yearly (drawn from long.population) instead of a single
static ACS 2018-2022 value. Adds pop_source column with values
'census_f33' or 'unavailable'.

R/spending.R

@@ -143,18 +143,24 @@ cog_spending <- function(govid, years, category = NULL,
 .attach_per_capita <- function(result, con, govid) {
   if (nrow(result) == 0L) {
     result$amt_per_capita_nominal <- numeric(0)
+    result$pop_source <- character(0)
     return(result)
   }
+  years_lit <- paste(unique(as.integer(result$year)), collapse = ",")
   sql <- sprintf(
-    "SELECT canonical_govid, population_acs
-     FROM canonical_fips_xwalk
-     WHERE canonical_govid IN (%s)",
-    .sql_lit_chr(govid)
+    "SELECT canonical_govid, year, population
+     FROM gov_population_yearly
+     WHERE canonical_govid IN (%s)
+       AND year IN (%s)",
+    .sql_lit_chr(govid), years_lit
   )
   pops <- tibble::as_tibble(DBI::dbGetQuery(con, sql))
-  result <- dplyr::left_join(result, pops, by = "canonical_govid")
-  result$amt_per_capita_nominal <- result$amt_nominal / result$population_acs
-  result$population_acs <- NULL
+  result <- dplyr::left_join(result, pops,
+                             by = c("canonical_govid", "year"))
+  result$amt_per_capita_nominal <- result$amt_nominal / result$population
+  result$pop_source <- ifelse(is.na(result$population),
+                              "unavailable", "census_f33")
+  result$population <- NULL
   result
 }