How many standards are there, when the launch date was 17.04.2006?
CREATE TABLE "table1_19246_1" (
  "carrier" text,
  "standard" text,
  "frequency" text,
  "connection_speed" text,
  "launch_date_dd_mm_yyyy" text
);
SELECT COUNT("standard") FROM "table1_19246_1" WHERE "launch_date_dd_mm_yyyy"='17.04.2006';