The Boston house-price data of Harrison, D. and Rubinfeld, D.L. 'Hedonic
 prices and the demand for clean air', J. Environ. Economics & Management,
 vol.5, 81-102, 1978.   Used in Belsley, Kuh & Welsch, 'Regression diagnostics
 ...', Wiley, 1980.   N.B. Various transformations are used in the table on
 pages 244-261 of the latter.

 Variables in order:
 CRIM     per capita crime rate by town
 ZN       proportion of residential land zoned for lots over 25,000 sq.ft.
 INDUS    proportion of non-retail business acres per town
 CHAS     Charles River dummy variable (= 1 if tract bounds river; 0 otherwise)
 NOX      nitric oxides concentration (parts per 10 million)
 RM       average number of rooms per dwelling
 AGE      proportion of owner-occupied units built prior to 1940
 DIS      weighted distances to five Boston employment centres
 RAD      index of accessibility to radial highways
 TAX      full-value property-tax rate per $10,000
 PTRATIO  pupil-teacher ratio by town
 B        1000(Bk - 0.63)^2 where Bk is the proportion of blacks by town
 LSTAT    % lower status of the population
 MEDV     Median value of owner-occupied homes in $1000's
