The ratings on Burkina Faso are constrained by a low level of economic development. GDP per capita is among the lowest of any rated sovereign, at an estimated $444 in 2006, and human development indicators are very weak. The ratings are also constrained by a lack of fiscal flexibility, due to the low level of domestic government revenues. These are estimated at just 12.2% of GDP in 2006, reflecting the narrow tax base and a large informal sector. General government deficits have averaged about 4% of GDP in recent years (including grants). The deficit is projected at about 4.2% of GDP in 2006, which is likely to be financed by donor flows. That said, the ratings on Burkina Faso are