The Barclays U.S. Aggregate Bond Index was launched in 1976. Since its 1976 inception, the index’s worst year has been 1994 (-2.92%). Since 1993, the index has had just two negative years, 1994 and 1999 (a loss of ~ 1%). From the beginning of 2013 to the end of August 2013, the index had a total return of -6.8%.
Over the past 15 years (not including 2013), the Aggregate Bond Index has had a maximum drawdown of 3.8% while real assets suffered a 68.6% loss, high-dividend stocks had a maximum loss of 60.2% and high-yield bonds dropped as much as 33.3%.