You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Universal_Studios

Context:
Goetz set out an ambitious schedule. Universal-International became responsible for the American distribution of Rank's British productions, including such classics as David Lean's Great Expectations (1946) and Laurence Olivier's Hamlet (1948). Broadening its scope further, Universal-International branched out into the lucrative non-theatrical field, buying a majority stake in home-movie dealer Castle Films in 1947, and taking the company over entirely in 1951. For three decades, Castle would offer "highlights" reels from the Universal film library to home-movie enthusiasts and collectors. Goetz licensed Universal's pre–Universal-International film library to Jack Broeder's Realart Pictures for cinema re-release but Realart was not allowed to show the films on television.

Question:
In what year did Universal-International take over Castle Films?

1951