Here are spreadsheets with summaries of yearly wireless usage for each library.
The best way of measuring Meraki wireless statistics is to take the daily average of unique clients from the Summary reports and multiply it out by 365. The maximum range that Meraki will use for the Summary Report is 6 months. Say the monthly average for a library for January through June is 68. For the rest of the year the daily average is 99. That averages out to 84 distinct clients per day. Multiply that by 365 and you get 30,660.
To be counted as a unique client, a wireless user has to pass at least 1 KB of traffic while connected to the libraries' wifi access point. Passing wifi users may get 'associated' with the library access point just by walking in if their device is set to do so, but they won't necessarily be counted.
You can access more detailed statistics (in real time and always up to date) on the Meraki dashboard here.
Within the Meraki dashboard, under the Organization category to the left, click on Summary Report. Then under Networks, select a single network and then your location. Near the top of the page, to the right of the Summary Report heading, there is a drop-down list where you can select a date range, or just the last week or month. Choose the range you want to see and click on the Update button.
The page will now display the statistics for the last month. The most useful numbers are probably in the Client Stats box which displays Total Unique Clients, Average # of Clients Per Day, and Average Usage Per Client.
If you look at the top right portion of the page, you'll see an Email this Report button and a Schedule Report Email button. I recommend you use the Schedule button to have the Meraki send you a monthly report. You can have it sent to more than one email address as well.
For more in-depth statistics, look under Organization on the left side of the dashboard, and choose Location Analytics.
The entries below are from when we used Raspberry Pi stats boxes to manage wireless statistics.
2016
2015
2014
2013
2012
2011