In August 2015, Czech GDP growth was 4.4%, making the Czech economy the highest growing in Europe. On 9 November 2015, unemployment in the Czech Republic was at 5.9%, the lowest number since February 2009. In September 2016, the unemployment was at 4.0%. In 2016, for first time since 1995, Czech Republic had budget surplus 61 billion CZK. In the year ending by Summer 2017, the Czech GDP grew by 4.7%, the third fastest in Europe, and unemployment was at 3% or 4% in the European or national conventions, by far the lowest rate in Europe. Dividends worth CZK 289 billion were paid to the foreign owners of Czech companies in 2016.
Answer this question: How many years has passed since the  lowest unemployment rate was last calculated?
6