This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.

At the age of 21 he settled in Paris. Thereafter, during the last 18 years of his life, he gave only some 30 public performances, preferring the more intimate atmosphere of the salon. He supported himself by selling his compositions and teaching piano, for which he was in high demand. Chopin formed a friendship with Franz Liszt and was admired by many of his musical contemporaries, including Robert Schumann. In 1835 he obtained French citizenship. After a failed engagement to Maria Wodzińska, from 1837 to 1847 he maintained an often troubled relationship with the French writer George Sand. A brief and unhappy visit to Majorca with Sand in 1838–39 was one of his most productive periods of composition. In his last years, he was financially supported by his admirer Jane Stirling, who also arranged for him to visit Scotland in 1848. Through most of his life, Chopin suffered from poor health. He died in Paris in 1849, probably of tuberculosis.
At what age did Frédéric move to Paris?