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.
Question: How many years were there between the Czech Republic's surplus reaching 61 billion CZK?
Answer: 21