Month	Number Of Units
1954-01-01	54801.0
1954-02-01	65574.0
1954-03-01	93438.0
1954-04-01	99595.0
1954-05-01	90981.0
1954-06-01	104294.
1954-07-01	96214.0
1954-08-01	98195.0
1954-09-01	96114.0
1954-10-01	93806.0
1954-11-01	87475.0
1954-12-01	76020.0
1955-01-01	77413.0
1955-02-01	76997.0
1955-03-01	114494.
1955-04-01	118576.
1955-05-01	117750.
1955-06-01	113158.
1955-07-01	97497.0
1955-08-01	106353.
1955-09-01	95739.0
1955-10-01	88234.0
1955-11-01	69728.0
1955-12-01	56692.0
1956-01-01	61836.0
1956-02-01	70095.0
1956-03-01	92265.0
1956-04-01	97135.0
1956-05-01	94737.0
1956-06-01	85785.0
1956-07-01	80541.0
1956-08-01	85441.0
1956-09-01	68625.0
1956-10-01	76829.0
1956-11-01	61051.0
1956-12-01	47543.0
1957-01-01	50837.0
1957-02-01	54408.0
1957-03-01	72778.0
1957-04-01	80501.0
1957-05-01	84149.0
1957-06-01	75354.0
1957-07-01	73712.0
1957-08-01	78097.0
1957-09-01	70950.0
1957-10-01	75230.0
1957-11-01	55493.0
1957-12-01	48813.0
1958-01-01	53472.0
1958-02-01	47995.0
1958-03-01	68710.0
1958-04-01	85619.0
1958-05-01	86292.0
1958-06-01	88330.0
1958-07-01	96479.0
1958-08-01	91652.0
1958-09-01	93594.0
1958-10-01	98665.0
1958-11-01	80974.0
1958-12-01	67802.0
1959-01-01	68346.0
1959-02-01	71071.0
1959-03-01	108330.
1959-04-01	116986.
1959-05-01	110628.
1959-06-01	109375.
1959-07-01	102082.
1959-08-01	96705.0
1959-09-01	92848.0
1959-10-01	86032.0
1959-11-01	68058.0
1959-12-01	66035.0
1960-01-01	56999.0
1960-02-01	60484.0
1960-03-01	81196.0
1960-04-01	91265.0