Here is something unmistakably common in Africa: the continent's aging and long-serving presidents.

Its five longest presidencies stretch between 29 and 36 years, adding to a cumulative 169 years. Their longevity in office is

matched by their old age, ranging from 71 to 91 years, and a combined 390 years.

Gabon's Omar Bongo had been president for a whopping 41 years when he died in office at the age of 73 in 2011. Hastings 

Banda, Malawi's self-proclaimed president for life, was in his late 90s when he was ousted from office in 1994. Zimbabwe's 

Robert Mugabe is 91, making him the oldest leader in the world.

The average age of the ten oldest African leaders is 78.5, compared to 52 for the world's ten most-developed economies.

Arguably, compared to other continents, Africa has a very small proportion of younger leaders between 35 and 55. 

Paradoxically, the continent has the youngest population in the world, with a median age of 19.5 years according to the U.N.

Old and out of touch

Africa has a leadership age gap disconnect between the leaders and the led. To put it into context, 85% percent of Angolans 

were not born when Dos Santos came into power in 1979. 83% of Zimbabweans were born after Mugabe first came into power as 

prime minister in 1980, while 79% percent of Ugandans were born after Museveni took over power in 1986.

On average, only between 15% to 21% of their citizens were alive when these presidents took the reins.

So, with a burgeoning youthful demography at the bottom, the political top is disturbingly a graying lot. The issue here is 

the age at which African leaders continue to hold the fort and ultimately refuse to unclench their grip on power.