The number of telephone calls (in tens of millions) made in Belgium from 1950-1973.
A data frame with 24 observations on the following 2 variables.
years since 1950 AD
number of telephone calls in tens of millions
Rousseeuw, P.J. and Leroy, A.M. (1987), Robust Regression and Outlier Detection, New York: Wiley.
Hettmansperger, T.P. and McKean J.W. (2011), Robust Nonparametric Statistical Methods, 2nd ed., New York: Chapman-Hall.
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