How to view past years maps (2010-2020)

As @SomeoneElse has said the key issue is that many are unlikely to have been mapped, particularly in the timeframe before around 2014. You may be interested in some work I did on patterns of mapping retail outlets over time by local authority area.

You could use my techniques to get historical data for all cafes in Warwickshire mapped on OSM. It's fairly technical and requires compiling osmium-tool, some UNIX scripting and familiarity with SQL and PostGIS.

An alternative for smaller areas is to run a series of overpass queries with attic data. Unfortunately these only go back to Sept 2012, but they're certainly a way of sense checking the approach. These queries are for cafes in Warwickshire on 30th Sept 2012 (200 ish) and now (~580).

Another source of data which may work for some local authorities, and which ought to not suffer from the completeness issue, is Food Hygiene Ratings (FHRS). The FSA do not publish historical data, but may retain it. I have complete dumps of this data for various dates between (roughly) 2013 and 2017.

Lastly both OSM and FHRS have a generic café description. Not all cafes will be coffee shops, some will be tea shops and others greasy spoons. More recent entries may be dessert or shish cafes both of which I've noticed increasing in the past 5 years. I suspect most cafes are not tagged in detail as to precise type (and this is not available on FHRS which lumps them with restaurants).

For small areas standard on-line commercial directories may be a useful source of info as they seem to be very poor at removing outdated retail locations. Other places which could be useful to supplement a classification are local forums: people living in an area can often demonstrate fantastic recall of shops going back 50 years or so.

A couple of point items from Nottingham of coffee shop cafes which entered & left the market in your timeframe: Smythsons from 2012-2018, Leaf & Bean 2013-2014, The Footman's Rest (not really a coffee shop), 2018-2019.

In practice I think you'll need to use multiple sources of data, but OSM may be a good start in Birmingham.

You'll also have the problem that once an area has been "mapped", it relies on there being regular re-surveys to spot the changes - almost every time I go into my local town centre I notice at least one shop has changed, but that's without me even checking OSM and there might be many more. One non-coffee shop related example: Lloyds TSB split into two separate banks back in 2013 and we still have loads of objects bearing the "Lloyds TSB" name - https://overpass-turbo.eu/s/PZm

The problem, as you already say, is:

for instance the coffee shop might have been opened in 2000 but only appeared on a map in 2009.

However, maybe you could try and control for "things being mapped in an area in OSM" by also taking into account:

• Those coffee shops that took over existing premises (i.e. it was a different sort of shop, but is now a coffee shop)
• The rise of other shops in the same area. If a coffee shop "appeared" on the street at the same time as all the other shops, then clearly that street was only mapped at all at the time that they all appeared.

If you're not interested in the overall numbers of coffee shops and just want a few case studies, then it's pretty straightforward. If you do want to measure overall numbers, then you'll need to use some clever statistics to model change. You won't be able to assume an even rate of mapping across the West Midlands, but you might be able to talk to some of the people who did it - try getting in touch with Mappa Mercia.