BRUSSELS, Sept 2 - The euro zone jobless rate was 8.9 percent in July, unchanged from the three-and-a-half-year high set the previous month, the European Union statistics office said on Tuesday. The unemployment rate of the 12-member bloc is at its highest since December 1999, a Eurostat official said. A breakdown of the data, which was in line with economists' expectations, showed Spain had the highest unemployment rate in the region at 11.4 percent. Eurostat estimated that 12.5 million people were unemployed in the euro zone in July.//