A object of class data.frame with 215 rows and 2 columns:
X
Monthly outward station movements.
Y
Montly inward station movements.
References
Thompson, H. E. and Tiao, G. C. (1971) "Analysis of Telephone
Data: A Case Study of Forecasting Seasonal Time Series," Bell Journal of
Economics, The RAND Corporation, vol. 2(2), pages 515-541, Autumn.