Name the south american rank for venezuela
CREATE TABLE "list_of_country_by_historical_gdp_ppp_pe" (
  "south_american_rank" real,
  "world_rank" real,
  "nation" text,
  "2011_imf" text,
  "2008_cia_factbook" text
);
SELECT MIN("south_american_rank") FROM "list_of_country_by_historical_gdp_ppp_pe" WHERE "nation"='Venezuela';