1948  147.2                           
  1949  149.8                           
  1950  152.3                           
  1951  154.9                           
  1952  157.6                           
  1953  160.2                           
  1954  163.0                           
  1955  165.9                           
  1956  168.9                           
  1957  172.0                           
  1958  174.9                           
  1959  177.8                           
  1960  180.7                           
  1961  183.7                           
  1962  186.5                           
  1963  189.2                           
  1964  191.9                           
  1965  194.3                           
  1966  196.6                           
  1967  198.7                           
  1968  200.7                           
  1969  202.7                           
  1970  204.9                           
  1971  207.0