context: In 2015 the nominal GDP of the citystate Berlin totaled €124.16 (~$142) billion compared to €117.75 in 2014, an increase of about 5.4%. Berlins economy is dominated by the service sector, with around 84% of all companies doing business in services. In 2015, the total labour force in Berlin was 1.85 million. The unemployment rate reached a 24-year low in November 2015 and stood at 10.0% . From 2012-2015 Berlin, as a German state, had the highest annual employment growth rate. Around 130,000 jobs were added in this period.
question: How many years did Berlin have the highest annual employment growth rate?
answer: 3