What is the group name on the date of 20 July 1999?
CREATE TABLE "national_conservatives" (
  "group_name" text,
  "english_abbr" text,
  "french_abbr" text,
  "formal_european_parliament_name" text,
  "from" text
);
SELECT "group_name" FROM "national_conservatives" WHERE "from"='20 july 1999';