What is the greek national account when 1997 is 6.1?
CREATE TABLE "table1_27146868_1" (
  "greek_national_account" text,
  "1970" text,
  "1980" text,
  "1990" text,
  "1995" text,
  "1996" text,
  "1997" text,
  "1998" text,
  "1999" text,
  "2000" text,
  "2001_1" text,
  "2002" text,
  "2003" text,
  "2004" text,
  "2005" text,
  "2006" text,
  "2007" text,
  "2008" text,
  "2009" text,
  "2010" text,
  "2011" text,
  "2012" text,
  "2013_2" text,
  "2014_2" text,
  "2015_3" text
);
SELECT "greek_national_account" FROM "table1_27146868_1" WHERE "1997"='6.1';