Oh, this is knowable, a quick search says the top 1% owns 32% of the wealth (I know this isn't income, so not perfect) but given that I'm going to say I think 26% is either fine or too low.
Based on a reported $820k mean income for the top 1% of earners vs something like 47k for everyone else (US figures), it'd be about 15% of total income being earned by the top 1%, which is lower than I would've thought.