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:
Westminster_Abbey

Context:
The bells at the abbey were overhauled in 1971. The ring is now made up of ten bells, hung for change ringing, cast in 1971, by the Whitechapel Bell Foundry, tuned to the notes: F#, E, D, C#, B, A, G, F#, E and D. The Tenor bell in D (588.5 Hz) has a weight of 30 cwt, 1 qtr, 15 lb (3403 lb or 1544 kg).

Question:
When were the ten bells cast?

1971