A data set from the MLC++ machine learning software for modeling customer
churn. There are 19 predictors, mostly numeric: state (categorical),
account_length area_code international_plan (yes/no),
voice_mail_plan (yes/no), number_vmail_messages
total_day_minutes total_day_calls total_day_charge
total_eve_minutes total_eve_calls total_eve_charge
total_night_minutes total_night_calls
total_night_charge total_intl_minutes
total_intl_calls total_intl_charge, and
number_customer_service_calls.