Activity maps for whole the DPD-era (1974–2014). Panel (A) shows the migration of the AL on the northern hemisphere. The black markers mean the longitudinal belts of most enhanced sunspot activity (AL) in certain CRs. Panel (B): the same as Panel (A), but for the southern hemisphere. Panel (C) represents the temporal variation of the International Sunspot Number (ISSN). The numbers of the solar cycles are also marked.