Complex sentence: During the last 50--60 years, the number of Armenians in Cyprus has decreased due to emigrations to other countries and integration into the broader Cypriot society, including intermarriage; their number today is smaller than it was 80 or 90 years ago.
Split into simpler sentences: During the last 50--60 years the number of Armenians in Cyprus has decreased due to emigrations to other countries and integration into the broader Cypriot society, including intermarriage. As a result their number today is smaller than it was 80 or 90 years ago.