The euro zone’s trade surplus rose year-on-year in July as exports grew faster than imports, pointing to a positive contribution to economic growth at the start of the third quarter, the European Union’s Statistics office data showed. Eurostat said the non-seasonally adjusted external trade surplus of the 18 countries sharing the euro was 21.2 billion euros (16.86 billion pounds) in July, up from 18.0 billion in July 2013.