Conversation so far:
What was Vaudeville?
Vaudeville is a theatrical genre of variety entertainment born in France at the end of the 19th century.
What was Bill Robinson's role in Vaudeville?
By 1912, Bill Robinson was a full partner in the duo, which had become primarily a tap dancing act, booked on both the Keith and Orpheum Circuits.
Did Vaudeville see any success?
Bill Robinson matured and began working as a solo act, increasing his earnings to an estimated $3,500 per week.

Question: How long did he perform solo?
Self-contained rewrite: How long did Bill Robinson perform solo?