In the postwar era, America had more than other countries until, approximately, the petira of Rav Moshe, Rav Yaakov and the Satmar Rebbe. Afterwards Eretz Yisroel had more.
In the pre-inquisition era, the Sephardic lands had the great Gedolei HaTorah. Ever since the Spanish expulsion, the great Gedolei HaTorah have by and large been in the Ashkenazic places.