CREATE TABLE table_2420 ("Political parties" TEXT, "% 2006" TEXT, "Seats 2006" FLOAT, "% 2001" TEXT, "Seats 2001" FLOAT, "% 1997" TEXT)

How many time was the political party the social democratic party of germany?
SELECT COUNT("% 2006") FROM table_2420 WHERE "Political parties" = 'Social Democratic Party of Germany'
SELECT COUNT("% 2006") FROM "table_2420" WHERE "Political parties" = 'Social Democratic Party of Germany'