Table schema:
CREATE TABLE table_name_94 (us_cham_rank INTEGER, next_highest_spender VARCHAR, year VARCHAR)

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?
SQL: SELECT MIN(us_cham_rank) FROM table_name_94 WHERE next_highest_spender = "national assn of realtors" AND year < 2012