You need to be more specific than that.
B bc you’re describing something or someone
Talk about how many have come through the years.
For example: Many immigrants have entered (whatever country, I'd assume America but you can fill in the blamk) but by far the most that have entered would be (number here) and (this percent) have stayed and.....
And if not that, maybe talk about how their cultures have affected the world or another country because of immigration. I hope that helps!
Answer: The journal of someone who was there at the time.
Explanation: The journal of a person who was present at the fall of the Berlin wall would be a perfect source, or footage of the event, or anything first-person. People who were actually there and participated are always the best sources for any historical event. (: