user: Question: Which US Cham Rank is the lowest one that has a Next Highest Spender of national assn of realtors, and a Year smaller than 2012?
Columns: ['Year', 'US Cham. Rank', 'US Cham. Spending', 'Next Highest Spender', 'Next Highest Amount']
Types: ['real', 'real', 'text', 'text', 'text']
Sample row: [2012.0, 1.0, '$136,300,000', 'National Assn of Realtors', '$41,464,580']
SQL:

assistant: SELECT MIN("US Cham. Rank") FROM "Table" WHERE "Next Highest Spender" = 'national assn of realtors' AND "Year" < 2012.0;