How many countries spent $83.7 billion on international tourism in 2012?
CREATE TABLE "international_tourism_expenditure" (
  "rank_2012" real,
  "country" text,
  "unwto_region" text,
  "international_tourism_expenditure_2011" text,
  "international_tourism_expenditure_2012" text,
  "pct_change" text
);
SELECT COUNT("pct_change") FROM "international_tourism_expenditure" WHERE "international_tourism_expenditure_2012"='$83.7 billion';