Turkey's industrial production increased 4.7 percent in March, compared with the same month last year, the Turkish Statistical Institute ("TÜİK" in Turkish) said in a statement on Friday.Total output increased 2.2 percent from the previous month, the statement said.The change surprised analysts who had forecast a rise of 1.7 percent on average and the new data was the strongest industrial output figure since October of last year."The new data suggesting a robust growth performance amid recent interest rate-growth-inflation debates raises the probability of growth performance that will also exceed forecasts," Adnan Çekcen, a financial analyst at Destek Securities in Istanbul, said.Production had risen 1 percent in February year-on-year, reversing a 2.2 percent drop in January. The Mining and Quarrying Index increased 3.8 percent and the Manufacturing Index increased 5 percent. The Electricity, Gas, Steam and Air Conditioning Supply Index also increased 3 percent in March 2015, compared with the same month last year.Industrial output figures are very important since they are deemed as a guide to growth data, Çekcen said. They can be useful to the central bank as a guide in making interest rate decisions, but he warned: "We should see the actual growth figures since industrial output figures are just a preliminary gauge".Interest rates are matter of debate in Turkey as government has repeatedly criticized the central bank for maintaining a tight monetary policy which limits growth. The central bank has maintained high interest rates and has linked interest rate decisions to the inflation outlook.