Rome, January 9 - Italy's public deficit fell significantly in the first nine months of 2012 thanks to tax hikes that took the tax burden up to 44.8% in this period, Istat said Wednesday. The tax burden in the same period of 2011 was 43.2%. The national statistics agency said the ratio between the deficit and gross domestic product for the first nine months of 2012 was 3.7%, 0.5% better than in the equivalent period of the previous year. It added that the deficit-GDP ratio fell to 1.8% in the third quarter of 2012, 0.7% lower than in the same three months in 2011. Istat said the new and much-criticised IMU property tax, introduced by outgoing Premier Mario Monti's emergency government of unelected technocrats, was the driving force of higher tax revenues. The tax hikes were part of austerity measures Monti's government passed to put Italy on course to balance the national budget in structural terms this year and move the country away from the centre of the eurozone debt crisis.