How many stations in 2011-12 had volume of 11580 in 2008-09?
CREATE TABLE "table1_1470706_1" (
  "station_name" text,
  "2002_03" real,
  "2004_05" real,
  "2005_06" real,
  "2006_07" real,
  "2007_08" real,
  "2008_09" real,
  "2009_10" real,
  "2010_11" real,
  "2011_12" real
);
SELECT COUNT("2011_12") FROM "table1_1470706_1" WHERE "2008_09"=11580;