NEW YORK ( TheStreet) -- Emerging markets bond funds have been rallying. The funds returned 15.0% this year, outdoing the Barclays Capital Aggregate Bond ( LAG) index by 11 percentage points, according to Morningstar. Investors have taken notice, pouring $19 billion into the funds this year, a huge inflow for a category with $73 billion total assets.Can emerging bonds continue to deliver solid returns? Probably. The bonds pay compelling yields. At a time when 10-year Treasuries yield 1.65%, some emerging markets funds yield more than 5.0%. Besides paying rich yields, many countries in Latin America and Asia boast strong balance sheets. That has special appeal in an era when developed countries are plagued with huge debt burdens. After struggling with financial crises in the 1990s, many emerging countries tightened their belts, reducing budget deficits and paying down debts. As a result, ratings agencies have upgraded many emerging countries, including Brazil, Turkey, and Russia, that were once considered below-investment grade. The upgrades have helped bond prices to rise sharply. TGEIX). At the start of the financial crisis in 2008, developed countries had debt levels that were equal to 80% of their gross domestic products. Since then the debt climbed to 110% of GDP. During the same period, the debt figure of developing countries declined from 35% to 34%.