First checkout the "Number of Wining Candidates". You can see that pro-establishment always has more seats than pan-democracy. However, in year 2013's Hong Kong district council election, there is one switching point. In terms of abosolute number of votes that support the winning candidates, pan-democracy is higher than pro-establishment. You can click "Absolute Number of Votes" to see the difference.
How?
You can search online for GeoJSON files organised by the open data community. We use 2blam/HK-geojson in this case. Right side is the map to show votes winned by "Other" camp (non pro-establishment and non pan-democracy) in the year 2015.
Problems and future directions?
How?