If you're trying to record verbatim what someone is saying, you could easily have to type much, much faster than that.
Stenographers are often required to type at least a hundred WPM faster than you type, and some people speak even faster than that. The demands are even higher when more than one person is talking at the same time and you're trying to record them both.
There are some tricks one could use to speed up plain old QWERTY, however. In particular, you could use macros. That's essentially what stenographers use on their special steno keyboards. A single chord will translate in to a full sentence. Likewise, you could trigger a macro on a QWERTY keyboard with a single chord and that can boost your WPM significantly, if you use a lot of them.
The vast majority of people are typing up some sort of copy or code, both of which are limited by thinking speed if you're anywhere above 80wpm or so.
Even writing a relatively casual e-mail I find myself limited by thought speed rather than typing. I can type a sustained 120-150wpm but frankly it's mostly a party trick, I don't think it makes me any more productive than someone typing 60-80wpm.
Edit: I stand by this. Auctioneers do provide a good counter example but much of what they say is just repeated phrases.
Here's an example of a professional stenographer dealing with 300+ wpm days (search "300wpm" in this page): https://jadeluxe.wordpress.com/2014/12/30/year-in-career-201...
Yes they do. 230 wpm is close to the upper limit for natural speech, but bursts of speech at that rate are quite common if the speaker is in a heightened emotional state or they are trying to convey a lot of information quickly.
Research into subtitling (closed captioning) by the BBC and OFCOM found that live programmes normally have bursts of speech at over 200 wpm. The BBC article below includes a sample clip of a presenter reading a news report at 230 wpm; while it sounds rushed and the presenter occasionally stumbles over a word, it does not sound completely unnatural.
https://www.bbc.co.uk/rd/blog/2015-09-how-fast-should-subtit...
https://www.ofcom.org.uk/__data/assets/pdf_file/0011/41114/q...
Average speaker is 150, an auctioneer is 250-400, the fastest person. The fastest talkers male and female can recite over 500,600 words per minute.
People can certainly and some people while exited/upset may.
Someone speaking a language like Chinese, where most of the words are single syllables, could probably speak a lot faster than someone speaking, say, German, where the words are often super long.
That's just my mostly uneducated guess, though. It'd be interesting to see some real-world comparisons of this.
I realise 500/600 looks like 5/6, but 500,600 reads to me as 500600. Maybe | is a good unambiguous character to use for "or".
As Y_Y already indicated:
> I realise 500/600 looks like 5/6 ….
If we're going to fuss about typography, these things:
> 500-600 wpm; 35-75 Kph; 2-3 grams.
are hyphens, and you want an en-dash: 500–600 wpm instead of 500-600 wpm.
Most alternative keyboard layouts reduce hand motion by putting the most used letters on the home row.
(This is especially important in programming, where I sometimes lose track of where I was in my mind while I type.)