https://www.theguardian.com/world/2019/aug/18/hong-kong-huge... https://www.bbc.com/news/world-asia-china-48656471 At many different times in 2019, 1.7M-2M Hong Kong citizens, or 25% of the population, proudly protested in the streets and requested for their freedom. If only something good had came out of it. Now it's sunk to what China's best at: false arrests: https://www.reddit.com/r/HongKong/comments/mc5bah/young…
I live in HK. 1.7M-2M is a really large exaggeration.
Satellite imagery is likely the best way to estimate.
The massive crowds in slow march peaceful protest videos I saw were astonishing.
However if we extrapolate that not everyone who'd support it or are silently supporting it - what % of people available to protest/march were out?
Edit to add: downvoting a question asking for trustworthy, quantifiable sources - you're failing.