In 2018, sitting leaders relinquished power in South Africa and Ethiopia. Zimbabwe elected a new leader after 37 years of rule by former President Robert Mugabe. Peaceful power transitions were also seen in Liberia, Sierra Leone and Mali. But while many find those trends encouraging, the opposite is also true in countries where some of world's longest serving leaders continue to hold power. VOA correspondent Mariama Diallo reports on the overall trends that are sparking both hope and worry.