Large-scale immigration over the last century and a half has led to a more multicultural society; beginning with the French Revolution, and further codified in the French Constitution of 1958, the government is prohibited from collecting data on ethnicity and ancestry; most demographic information is drawn from private sector organisations or academic institutions. In 2004, the ''Institut Montaign''e estimated that within Metropolitan France, 51 million people were White (85% of the population), 6 million were Northwest African (10%), 2 million were Black (3.3%), and 1 million were Asian (1.7%).