CREATE TABLE "national_parks" (
  "year" real,
  "park" text,
  "artist" text,
  "mintage" real,
  "issue_price" text
);

Question: What is the lowest mintage in a year earlier than 2005?
SQL: SELECT MIN("mintage") FROM "national_parks" WHERE "year"<2005;

Question: What is the sum of all mintage created by Pierre Leduc?
SQL: SELECT SUM("mintage") FROM "national_parks" WHERE "artist"='pierre leduc';