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9. Slovenia

Old/young ratio: 1.253:1
65 years & over: 16.8%
0-14 years: 13.4%

The retirement age in Slovenia is currently among the lowest in the EU, at 57 for women and 58 for men.

Part of the former Yugoslav republic, which was once considered a successful model for post-communist transition, Slovenia has faced a series of credit rating downgrades in the past year as its economy struggles with a high budget deficit, political instability and an expensive state pension system. Government reform to raise Slovenia's retirement age was rejected in a referendum in June last year, dealing a major blow to the country's plans to control its ballooning public debt. But, the current government is planning to raise the retirement age starting in next year. The World Bank predicts the average age for Slovenia will be 47.4 years in 2025 — among the oldest in the world.

The rapidly aging population has been a big burden on Slovenia's budget. From 2003 to 2009, the average annual increase in health expenditure was 7.1 percent, while GDP growth in the same period was 5.9 percent, according to the government figures. In 2009 alone, the nominal health expenditure grew by 7.1 percent, while Slovenia's GDP contracted 5.3 percent. Despite the increase in health-care spending, Slovenia is still below the average for OECD countries. Total health spending accounted for 9.3 percent of its GDP, compared to average of 9.5 percent in OECD countries in 2009.

Photo: Christian Kober | Getty Images