Greece revised yesterday the depth of the recession it suffered last year, saying that business activity had contracted by 7.1 percent instead of a previous estimate of 6.9 percent. The Greek statistics authority issued the new estimate of gross domestic product based on 2010 prices, a statement said. \"GDP (market prices) for 2011, calculated at 2010 prices, amounted to 206.4 billion euros ($269 billion) compared with 222.2 billion euros for 2010 (7.1 percent reduction),\" the statement said. \"The revisions of statistical results are an integral part of the statistical process and the national accounts (GDP and its components) are compiled in this context,\" it added.