Name the number of troops for troops per $1 billion being 2.45
CREATE TABLE "table1_30108346_1" (
  "country" text,
  "number_of_troops" real,
  "pct_of_total_troops" text,
  "troops_per_one_million_population" text,
  "troops_per_1_billion_usd_gdp" text
);
SELECT COUNT("number_of_troops") FROM "table1_30108346_1" WHERE "troops_per_1_billion_usd_gdp"='2.45';