What is the power of the unit built after 1995?
CREATE TABLE "diesel_multiple_units" (
  "type" text,
  "numbers" text,
  "year_built" real,
  "quantity_built" text,
  "power_horsepower" real,
  "max_speed_km_h" real
);
SELECT SUM("power_horsepower") FROM "diesel_multiple_units" WHERE "year_built">1995;