the tariffs charged to the US are openly available information. There are a lot. And they are often 50% or higher.

Very rarely are tariffs any kind of flat rate on everything from a country; generally, nations have tariffs on specific goods, usually for industries they want to protect. This makes it difficult to reasonably express the tariffs they charge as a single number, because it really isn't a single number.

But, using Canada as an example, it appears that at least the effective tariff rate fell from about 2.6% in 1988 to about 0.2% through the 2000s and 2010s, with effective US tariffs being in the same general range.

As others have pointed out (if harshly), the numbers purported to be 'reciprocal tariffs' on the chart are not in fact tariffs at all, they're just a percentage expression of the trade deficit ratio. They've put up a page explaining it, if one that I think perhaps is trying harder to make it sound complicated than to make it sound simple. You can see the equation at the bottom, the one with four variables; ε and φ are not country-specific, and since they've chosen ε to be 4 and φ to be .25, the two multiplied together effectively drop out of the equation altogether. Thus, we are left with a very simple calculation of (exports - imports)/imports - which has no immediate dependence upon any actually-charged tariffs at all.