Oct 9 (Reuters) - Slovak construction output rose by a real 21.6 percent year-on-year in August after 17.5 percent growth in July, the Statistics Office said on Monday. CONSTRUCTION OUTPUT Aug/06 July/06 Aug/05 pct change yr/yr 21.6 17.5 15.1 (Reporting by Martin Santa in Bratislava) ((For past economic data and analysts' forecasts, double click on <SK/ECON01>)) ((Editing by Alan Crosby; bratislava.newsroom@reuters.com; Reuters Messaging: martin.santa.reuters.com@reuters.net; +421 2 5341 8402)) Keywords: ECONOMY SLOVAKIA CONSTRUCTION