mining.def

  YEAR    QTR   PRO   POW

   Obs: 111  Quarterly observations from 1972(1) to 1999(3)

   YEAR = Year
    QTR = Quarter
    PRO = Index of mining production (seasonally adjusted) in the U.S.
    POW = Index of electric power use (seasonally adjusted) in the U.S.

    Variable |       Obs        Mean    Std. Dev.       Min        Max
-------------+--------------------------------------------------------
        YEAR |       111    1985.378    8.047647       1972       1999
         QTR |       111    2.486486    1.118968          1          4
         PRO |       111    104.6533    4.823451      97.08   118.5883
         POW |       111    90.05544    12.10262   60.82333   104.7297