I'd believe it. Wikipedia has a similar one [1] but it shows a bit more hydrogen than helium at higher elevation.
Awesome graph! Worth stating that the increase in the relative fraction of He isn't so much because there's a lot of He out there as because there's a lot less of everything else. Overall density falls off roughly exponentially but lighter elements have a longer tail.
So once you get out to a few earth radii quite a bit of what you see might be ionized helium but that doesn't mean you can do much with it.
Awesome graph! Worth stating that the increase in the relative fraction of He isn't so much because there's a lot of He out there as because there's a lot less of everything else. Overall density falls off roughly exponentially but lighter elements have a longer tail.
So once you get out to a few earth radii quite a bit of what you see might be ionized helium but that doesn't mean you can do much with it.
[1]: https://en.wikipedia.org/wiki/File:Chemical_composition_of_a...