How many solar systems are in the milky way galaxy?

So far, astronomers have found more than 500 solar systemsand are discovering new ones every year. Given how many they have found in our own neighborhood of the Milky Way galaxy, scientists estimate that there may be tens of billions of solar systems in our galaxy, perhaps even as many as 100 billion.

I'm pretty sure it's c. extremely gradual but not 100% sure though.

The reason why i feel that the theory of plate tectonics is correct because scientists have found dinosaur bones of the same species in africa, asia, and in the americas. which means that they must have been together at one point in time. plate tectonics is also how the hawaiian islands were formed. as the plate hawaii is on was moving north west, magma would melt through the sea bottom and hardening. forming into the island chain. plate tectonics also explains the mariana trench. two plates were moving away from each other and made a giant crack in the ocean floor running 2,550 kilometers (1,500 miles)  long.