The official number 78, which was used for Seine-et-Oise, was given to the new Yvelines "département", which is the largest amount of the former Seine-et-Oise (40% of the area of Seine-et-Oise). There were 198 communes in the south of Seine-et-Oise (32% of the area of Seine-et-Oise) that became part of the Essonne "département", and the official number 91 was assigned to this "département", a number that had been previously used for the Alger "département" in French Algeria). There were 184 communes in the north of Seine-et-Oise (22% of the area of Seine-et-Oise) that became part of the Val-d'Oise "département", and the official number 95 was assigned to this "département", a number that had never been used. Of the remaining 6% of Seine-et-Oise, 18 communes were grouped with 29 communes of the Seine "département" to create the Val-de-Marne "département", 16 communes of Seine-et-Oise were grouped with 24 communes of the Seine "département" to create the Seine-Saint-Denis "département", and the last 9 communes of Seine-et-Oise were grouped with 27 communes of the Seine "département" to create the Hauts-de-Seine "département". Thus, Yvelines, Val-d'Oise, and Essonne are altogether smaller than the former Seine-et-Oise "département" (5,658 km² for the Seine-et-Oise "département" vs. 5,334 km² for the three "départements"). The three "départements" of Yvelines, Essonne, and Val-d'Oise, plus the Seine-et-Marne "département", are altogether known in France as the "grande couronne" (i.e. "large ring", as opposed to the "small ring" of the suburbs closer to Paris). At the 1999 French census, the population of the former Seine-et-Oise was 4,554,426 inhabitants, its highest figure ever, as people relocate more and more from the center to the distant suburbs of the metropolitan area of Paris.