cant be 和 cant have been 的不同之处?

There cant have been so many people in the street so late at night.

There cant be so many people in the street so late at night.

请问此例句中，用 have been 和 be 句意上有哪些不同？ 正常状态的事件不应该用一般时态吗？

There cant have been so many people in the street so late at night. 推断过去的状况。

There cant be so many people in the street so late at night.推断目前的状况。