I don't disagree with what you have to say, but this statistic probably has the opposite effect of what you intended. It's telling me that it happened in 20% of elections since 1900. Most hard core third party voters would be pleasantly surprised to hear this ;-)
Then they would, objectively speaking, be complete idiots. It happens literally every major elections in other countries with better electoral systems.
For instance in NZ's 53rd General Election which just concluded, despite Labour functionally sweeping the election, four parties exceeded 5% of the vote. And while I'm not going to say that it happens every time, it's not an abnormal result at all for the country.
Furthermore, it misses the point I was underlying, which is that this only assists in funding the next election, which is only useful if you can transform this into a long-standing regular position, which has never happened. Getting 5% on an election doesn't in and of itself give you anything in the US.
1. 5% is a very high bar in the US, going back to the 1900 election it happened to 6 people in 6 elections: Taft (as the incumbent!) and Debs in 1912, La Follette in 1932, Wallace in 1968, Anderson in 1980 and Ross Perot in 1992 and 1996. It's basically a generational event. And even Perot couldn't convert two third-places into anything lasting, what's the point of getting matching funds for the next election if you're only going to waste the money again except worse?
2. the candidate must agree to very strict spending limits, putting them at a large disadvantage for actually achieving their 5%; worse, while the federal limit is rather high it's really an expenditure limit per state based entirely on the state's population, no focusing on states where you have a chance to make an impact
3. it's only matching funds, it's not a magic purse of money
4. no matter how you slice it, the spoiler effect is, well, in effect
That 5% line would be way more useful and relevant if you guys fixed your presidential election system first, both the voting system, and everything that's around (the funding, the PACs, etc…).
Third-party candidates are not viable under FPTP, third-party candidates are even less viable when the main two candidate literally spend hundreds of millions.