Month Million Square Feet 1956-01-01 12.6600 1956-02-01 14.8900 1956-03-01 20.8000 1956-04-01 20.7100 1956-05-01 15.8600 1956-06-01 15.2200 1956-07-01 18.8700 1956-08-01 15.8900 1956-09-01 15.6000 1956-10-01 13.9800 1956-11-01 15.4500 1956-12-01 12.1900 1957-01-01 17.0400 1957-02-01 15.4500 1957-03-01 16.6000 1957-04-01 13.4100 1957-05-01 15.3900 1957-06-01 20.7400 1957-07-01 15.3000 1957-08-01 13.1400 1957-09-01 11.8100 1957-10-01 14.0200 1957-11-01 11.5900 1957-12-01 11.7200 1958-01-01 8.87000 1958-02-01 7.64000 1958-03-01 9.51000 1958-04-01 6.83000 1958-05-01 11.2400 1958-06-01 8.08000 1958-07-01 11.4700 1958-08-01 12.6700 1958-09-01 8.44000 1958-10-01 12.1800 1958-11-01 9.44000 1958-12-01 7.64000 1959-01-01 7.86000 1959-02-01 9.17000 1959-03-01 11.5800 1959-04-01 16.8000 1959-05-01 15.8900 1959-06-01 12.5000 1959-07-01 13.9800 1959-08-01 13.6100 1959-09-01 14.5200 1959-10-01 17.4700 1959-11-01 14.2400 1959-12-01 12.3900 1960-01-01 11.5900 1960-02-01 10.5200 1960-03-01 14.5700 1960-04-01 16.3900 1960-05-01 18.4400 1960-06-01 14.3600 1960-07-01 19.0300 1960-08-01 16.6400 1960-09-01 14.5800 1960-10-01 16.7300 1960-11-01 15.4800 1960-12-01 11.0300 1961-01-01 9.61000 1961-02-01 8.55000 1961-03-01 12.9000 1961-04-01 13.2500 1961-05-01 13.1300 1961-06-01 11.9100 1961-07-01 13.3700 1961-08-01 18.9600 1961-09-01 12.3000 1961-10-01 10.5400 1961-11-01 14.3600 1961-12-01 13.9300 1962-01-01 10.5200 1962-02-01 11.4600 1962-03-01 16.9000 1962-04-01 16.3100 1962-05-01 17.5900 1962-06-01 13.8200 1962-07-01 15.2200 1962-08-01 20.1400 1962-09-01 11.8400 1962-10-01 16.4000 1962-11-01 13.7500 1962-12-01 11.9300 1963-01-01 10.5000 1963-02-01 12.9500 1963-03-01 15.0800 1963-04-01 13.8600 1963-05-01 20.4600 1963-06-01 19.1000 1963-07-01 16.5700 1963-08-01 21.3600 1963-09-01 15.2800 1963-10-01 19.2700 1963-11-01 15.0700 1963-12-01 11.6600