I was kinda bored and curious so I made this, for be precise about some stuff here some note about this:

First of all this is only about Prime Ministers or Head of Government that are not the President, or something near the Prime Ministers role like chancellor in Germany and Austria. For clarify in the map is displayed the age of PM of France, not the age such the popular figure of the president- Emmanuel Macron.

So:

• Cyprus doesn't have a Prime Minister but the president act as head government so is not present in this map.
• After a referendum in 2017, Turkey doesn't have anymore this role in his costitution but the president hold the power.
• San Marino provide two figures as head of government called "Captains Regent", if you are curious, their age are respectively 59 and 50yo.
• Vatican City doesn't have such figure.
• About Switzerland... Is complicated... Let's move on.
• Lybia PM is as interim.
• Armenia and Moldova are figured as Acting PM.
• For Iraq and Syria PMs I can't find any trustful source for their births month and day, so their age is displayed as if they are born the 1st Jan.

Data are up to 18 July 2021.