Year Percent 1950 4.71432 1955 4.46369 1960 4.23966 1965 4.13308 1970 3.84956 1975 3.85213 1980 4.02893 1985 3.95436 1990 4.18832 1995 4.60116 2000 4.43438 2005 4.43565 2010 4.47131 2015 4.30939 2020 4.19262 2025 4.18755 2030 4.37506 2035 4.82239 2040 5.55458 2045 6.48135 2050 7.72378 2055 9.03183 2060 10.3772 2065 11.76186 2070 13.31031 2075 14.66587 2080 16.07641 2085 17.5215 2090 18.97481 2095 20.39659 2100 21.78977