CLEAN : Crimes against humanity since 1991 in Eritrea: UN

The video discusses crimes against humanity, including enslavement, imprisonment, enforced disappearance, torture, persecution, rape, murder, and other inhumane acts. These crimes have been part of a widespread and systematic campaign against civilians since 1991.

What is the significance of the term 'widespread and systematic' in the context of the text?

How long has the campaign against the civilian population been ongoing?