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?
CREATE TABLE "us_chamber_lobbying_2002_2012" (
  "year" real,
  "us_cham_rank" real,
  "us_cham_spending" text,
  "next_highest_spender" text,
  "next_highest_amount" text
);
SELECT MIN("us_cham_rank") FROM "us_chamber_lobbying_2002_2012" WHERE "next_highest_spender"='national assn of realtors' AND "year"<2012;