Belgium Phone Calls 1950-1973

SUMMARY:
       The phones data frame has 24 rows and 2 columns.

DATA DESCRIPTION:
       This data frame contains the following columns:

year:     The last two digits of the year.
calls:    The number of telephone  calls  made  (in  millions  of
       calls).

SOURCE:
       The data were obtained from

       Rousseeuw, P.J. and Leroy, A.M. (1987)  Robust  Regression
       and Outlier Detection. John Wiley.

OTHER REFERENCES:
       Davison, A.C. and Hinkley, D.V. (1997)  Bootstrap  Methods
       and Their Application. Cambridge University Press.

       Venables, W.N. and  Ripley,  B.D.  (1994)  Modern  Applied
       Statistics with Splus. Springer-Verlag