What was the span of age estimates for the universe before Hubble refined the Hubble Constant?

Varying sometimes from 10 billion to 20 billion years

Prior to the definitive data provided by the Hubble Space Telescope regarding the Hubble Constant, cosmological models faced significant internal tension due to highly uncertain calculations for the age of the universe. The accepted estimates were broad and contradictory, varying significantly, with recorded figures sometimes spanning from as low as 10 billion years up to 20 billion years. This wide margin introduced fundamental problems when trying to align cosmological theory with observations of the oldest stars. Hubble's subsequent precise measurements utilizing Cepheid variables successfully narrowed this uncertainty down to the current figure of approximately 13.8 billion years, resolving a massive discrepancy in astrophysics.