user: Question: In 2011, how many tourists visited the country that had 23.4 million tourists in 2012?
Columns: ['Rank', 'Country', 'International tourist arrivals (2012)', 'International tourist arrivals (2011)', 'Change (2011 to 2012)', 'Change (2010 to 2011)']
Types: ['real', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'United States', '67.0 million', '62.7 million', '+6.8%', '+4.9%']
SQL:

assistant: SELECT "International tourist arrivals (2011)" FROM "Table" WHERE "International tourist arrivals (2012)" = '23.4 million';