DATA9-3:  Quarterly data from 1972.2 through 1993.4 for San Diego
   Gas and Electric Company
   reskwh = kilowatt-hour sales to residential customers (millions)
            at quarterly rates (Range 586.608 - 1512.306)
   nocust = average number of residential customers (thousands)
            (Range 459.903 - 1007.706)
   price  = average price in cents per kwh for the single family
            rate tariff (Range 2.207 - 12.42)
   cpi    = San Diego consumer price index (1982-84 = 100)
            (Range 36.54 - 150.9)
   incm =   Total personal income in millions of current dollars
            in San Diego county, at quarterly rates
            (Range 1815.148 - 13870.889)
   cdd    = cooling degree days - summation over the quarter of
            max[(daily max+min/2) - 65, 0], Range 0.374 - 973.493.
   hdd    = heating degree days - summation ver the quarter of
            max[(65 - (daily max+min/2), 0], Range 0.042 - 950.17.
   pop    = San Diego county population (thousands),
            Range 1422.64 - 2678.544.

SAMPLE 1 87
* Sample period 1972.2-1993.4
READ (DATA9-3) period reskwh nocust price cpi incm cdd hdd pop