You can go straight to the source, i.e. the audited FY2023 financial statement[0]. You're right that revenues from CPB contracts amount to single-digit million dollars (roughly $7mm in 2023) a year, out of >$300mm of total annual revenues; but also from the same document:
> National Public Radio, Inc. (“NPR Inc.”) a nonprofit membership corporation incorporated in 1970 following passage of the Public Broadcasting Act of 1967, as amended
> [American Coalition for Public Radio, a wholly-owned subsidiary,] supports the educational mission of publicly funded, noncommercial, educational radio stations, networks, and systems (collectively, “Public Radio”) [...] aims to secure robust federal funding
One can register some legitimate disappointment in a "national public" radio organization, breathed into law by Congress, turning into something rather nakedly partisan. That only 1% of revenues come from tax dollars has little to do with that part.
[0]: https://media.npr.org/documents/about/statements/fy2023/Nati...