What are the numbers next to the maelstrom entries on galaxy map

[Acid Mayhem]

In the 'Thargoid War Information' tab on the galaxy map, what do the numbers next to the Maelstrom names signify?
e.g. Maelstrom Taranis has 125 , Maelstrom Oya has 68.

Can't seem to find an answer

 

[ThinkingPortals]

How many systems affected by the Mael