What was the minor version released on April 16, 2008?
CREATE TABLE "windows" (
  "major_version" text,
  "minor_version" text,
  "web_kit_version" text,
  "operating_system" text,
  "release_date" text,
  "features" text
);
SELECT "minor_version" FROM "windows" WHERE "release_date"='April 16, 2008';