What were the results of the womens u20 when the mens 45 was  Sunwest Razorbacks def Northern Eagles?
CREATE TABLE "results_by_year" (
  "year" real,
  "mens_open" text,
  "womens_open" text,
  "mixed_open" text,
  "mens_u20" text,
  "womens_u20" text,
  "senior_mixed" text,
  "mens_30" text,
  "womens_30" text,
  "mens_35" text,
  "womens_35" text,
  "mens_40" text,
  "womens_40" text,
  "mens_45" text,
  "mens_50" text
);
SELECT "womens_u20" FROM "results_by_year" WHERE "mens_45"='SunWest Razorbacks def Northern Eagles';