Despite these barriers to access, health services have shown a trend toward improvement over the past twenty years. Child immunizations against such diseases as hepatitis B, diphtheria and measles increased an average of 60 percent in this period, indicating low but increasing availability of basic medical services and treatments. The Malagasy fertility rate in 2009 was 4.6 children per woman, declining from 6.3 in 1990. Teen pregnancy rates of 14.8 percent in 2011, much higher than the African average, are a contributing factor to rapid population growth. In 2010 the maternal mortality rate was 440 per 100,000 births, compared to 373.1 in 2008 and 484.4 in 1990, indicating a decline in perinatal care following the 2009 coup. The infant mortality rate in 2011 was 41 per 1,000 births, with an under-five mortality rate at 61 per 1,000 births. Schistosomiasis, malaria and sexually transmitted diseases are common in Madagascar, although infection rates of AIDS remain low relative to many countries in mainland Africa, at only 0.2 percent of the adult population. The malaria mortality rate is also among the lowest in Africa at 8.5 deaths per 100,000 people, in part due to the highest frequency use of insecticide treated nets in Africa. Adult life expectancy in 2009 was 63 years for men and 67 years for women.. How many more years for adult expectancy for women than men?