The consumer price index for the eurozone's largest economy rose 2.5 percent on a 12-month basis in October, compared with 2.6 percent in September, the national statistics office Destatis said in a statement. On a monthly basis, the index was unchanged. The final data confirmed a preliminary estimate published at the end of last month. As in previous months, rising household energy costs, in particular for heating oil and gas, were the main factor behind the elevated level of inflation, it said. Using the EU's Harmonised Index of Consumer Prices or HICP, which is the European Central Bank's inflation yardstick, the cost of living in Germany rose by 2.9 percent on a 12-month basis in October. The ECB aims to keep inflation close to, but below 2.0 percent.