How do big bang theorists/ non-creationists answer this question?

One set of measurements showed a trend, but the technique was not particularly precise. Modern precision measurement showed that the Sun is shrinking at half the stated rate, on average. If the old 6 foot value were true, then current measurements, could easily be part of a long term cycle. Mind you, every 2 hours 40 minutes, the Sun undergoes a 10km oscillation, so we know oscillation phenomena exist.