Very hard to measure.
Because the Internet is not a simple network, there are links of hugely varying capacities going all over the place, and many protocols use caches that are spread all over the world.
So, first define what you mean by bandwidth in the context of the whole network, and then we can start to make an answer.
See what I mean? That’s a snapshot in time too, it evolves.
That’s it projected a different way, with more detail… from 1999. You can bet it’s way more complex than that now.
The Internet topology is so complicated that just finding ways to draw it is an active research topic.