Serbia’s credit was downgraded by the ratings company Fitch “due to fiscal slippage and sluggish growth, reports Gordana Filipovic for Bloomberg. Serbia’s national debt is currently 63% of its GDP, but that is expected to increase to 70% by 2015, while GDP growth is expected to stay below 2% per year. Fitch gave Serbia a B+ credit rating, down from BB-, which is below investment grade, but none of the information that Fitch highlighted in its report is news to analysts. The downgrade is unlikely to change the facts on the ground, since the interest rates that Serbia has had…