Given that the second survey had been open to anyone from anywhere, I wondered where the responses had come from. I was also aware of a number of issues with streets not getting the second consultation delivered within the timescales that where promised, and wondered if the response data would show up any other areas where a lack of responses might show that there where issues with deliveries.
I therefore put in a Freedom of Information request via What Do They Know, which can be found here. I've taken the postcodes, and converted them to latitudes and longitudes using this website.
I then input the data into Google's Spreadsheet mapper, fiddled with it a little, and created this map showing where responses came from. I'm not sure it answers my original question, but it's still quite an interesting exercise, all using free tools that are floating around the web.