user: Question: In 2010, how many 1st venue cities were there? 
Columns: ['Year', '1st Venue', '2nd Venue', '3rd Venue', '4th Venue', '5th Venue']
Types: ['real', 'text', 'text', 'text', 'text', 'text']
Sample row: [2007.0, 'Sheffield', 'Mexico City', 'Nanjing', 'NA', 'NA']
SQL:

assistant: SELECT COUNT("1st Venue") FROM "Table" WHERE "Year" = 2010.0;