Why did the governors of the Reserve Bank of Australia raise its benchmark interest rate?

The governors of the Reserve Bank of Australia raised its benchmark interest rate to 3.25 percent, Tuesday, up from three percent. They say, (9) with Australia’s economic growth on track and the risk of a serious contraction past, it is time to gradually raise rates from their lowest level in 49 years.
    The central bank began cutting rates in September 2008, when they stood at 7.25 percent. At the time, the world was rapidly sinking into a crisis, with banks cutting off lending and several international financial institutions on the verge of collapse.