context: Warsaw, especially its city centre (Śródmieście), is home not only to many national institutions and government agencies, but also to many domestic and international companies. In 2006, 304,016 companies were registered in the city. Warsaw's ever-growing business community has been noticed globally, regionally, and nationally. MasterCard Emerging Market Index has noted Warsaw's economic strength and commercial center. Moreover, Warsaw was ranked as the 7th greatest emerging market. Foreign investors' financial participation in the city's development was estimated in 2002 at over 650 million euro. Warsaw produces 12% of Poland's national income, which in 2008 was 305.1% of the Polish average, per capita (or 160% of the European Union average). The GDP per capita in Warsaw amounted to PLN 94 000 in 2008 (c. EUR 23 800, USD 33 000). Total nominal GDP of the city in 2010 amounted to 191.766 billion PLN, 111696 PLN per capita, which was 301,1 % of Polish average. Warsaw leads the region of East-Central Europe in foreign investment and in 2006, GDP growth met expectations with a level of 6.1%. It also has one of the fastest growing economies, with GDP growth at 6.5 percent in 2007 and 6.1 percent in the first quarter of 2008.
question: How many companies were registered in Berlin in 2006?