Month	Thousand Units
1959-01-01	3.70000
1959-02-01	3.80000
1959-03-01	5.20000
1959-04-01	5.80000
1959-05-01	5.60000
1959-06-01	5.10000
1959-07-01	5.60000
1959-08-01	4.50000
1959-09-01	4.40000
1959-10-01	4.60000
1959-11-01	3.90000
1959-12-01	3.50000
1960-01-01	3.30000
1960-02-01	3.90000
1960-03-01	3.30000
1960-04-01	3.90000
1960-05-01	4.40000
1960-06-01	4.20000
1960-07-01	3.90000
1960-08-01	4.00000
1960-09-01	3.00000
1960-10-01	3.70000
1960-11-01	3.20000
1960-12-01	3.00000
1961-01-01	2.60000
1961-02-01	3.80000
1961-03-01	3.50000
1961-04-01	3.80000
1961-05-01	4.70000
1961-06-01	4.50000
1961-07-01	3.60000
1961-08-01	3.10000
1961-09-01	4.30000
1961-10-01	4.30000
1961-11-01	3.50000
1961-12-01	2.30000
1962-01-01	2.90000
1962-02-01	2.60000
1962-03-01	4.50000
1962-04-01	5.40000
1962-05-01	5.10000
1962-06-01	4.00000
1962-07-01	4.30000
1962-08-01	4.20000
1962-09-01	4.00000
1962-10-01	4.10000
1962-11-01	3.70000
1962-12-01	4.10000
1963-01-01	2.90000
1963-02-01	3.80000
1963-03-01	4.50000
1963-04-01	5.60000
1963-05-01	5.70000
1963-06-01	4.60000
1963-07-01	4.80000
1963-08-01	4.70000
1963-09-01	4.40000
1963-10-01	5.10000
1963-11-01	4.00000
1963-12-01	3.10000