DATA9-8:
  Annual data for estimating Domestic Revenue Passenger Miles.
  Source: Statistical Abstract of United States, 1947-1987.
  Data compiled by GRAHAM RUSHALL.
  pop   = population in millions (Range 144.83 - 243.915)
  rpm   = domestic revenue passenger miles in billions (Range 6 - 324.5)
  nop   = number of operators (airlines), Range 31 - 106.
  oprev = operating revenue from passengers in millions of dollars
          (Range 256 - 37309)
  gnp   = gross national product of United States in billions of dollars
          (Range 232.2 - 4526.7)
  accid = number of American planes in an accident (Range 12 - 69)
  fatal = number of fatalities from aircraft accidents (Range 0 - 460)
  regu  = dummy variable for airline regulation/deregulation
          = for 1 1979-87 and 0 for 1947-78.

SAMPLE 1 41
* Sample period 1947-1987
READ (DATA9-8) year pop rpm nop oprev gnp accid fatal regu