There was a 25% drop in Greece's GDP, connected with the bailout programmes. This had a critical effect: the Debt-to-GDP ratio, the key factor defining the severity of the crisis, would jump from its 2009 level of 127% to about 170%, solely due to the shrinking economy. In a 2013 report, the IMF admitted that it had underestimated the effects of so extensive tax hikes and budget cuts on the country's GDP and issued an informal apology. The Greek programmes imposed a very rapid improvement in structural primary balance (at least two times faster than for other Eurozone bailed-out countries). The policies have been blamed for worsening the crisis, while Greece's president, Prokopis Pavlopoulos, stressed the creditors' share in responsibility for the depth of the crisis. Greek Prime Minister, Alexis Tsipras, asserted that errors in the design of the first two programmes which led to a loss of 25% of the Greek economy due to the harsh imposition of excessive austerity.