Chart of Second Polish Republic - GDP per capita (1922-1938)

On top of this was the massive destruction left after both World War I and the Polish–Soviet War. There was also a great economic disparity between the eastern (commonly called Poland B) and western (called Poland A) parts of the country, with the western half, especially areas that had belonged to the German Empire being much more developed and prosperous. Frequent border closures and a customs war with Germany also had negative economic impacts on Poland. In 1924 Prime Minister and Economic Minister Władysław Grabski introduced the złoty as a single common currency for Poland (it replaced the Polish marka), which remained a stable currency. The currency helped Poland to control the massive hyperinflation. It was the only country in Europe able to do this without foreign loans or aid. The average annual growth rate (GDP per capita) was 5.24% in 1920–29 and 0.34% in 1929–38.

Reference 1: Int $ ..

Reference 2: 1922, 1929, 1930, 1931, 1932, 1933, 1934, 1935, 1936, 1937 and 1938.

Source: http://en.wikipedia.org/wiki/Second_Polish_Republic