In the event that this has been published, then consider this a request for a link. :-)
The street parking permit areas data IS published. And the polygons there include the area name, such as 6G. Nice. Could that data be extended with the number of parking spots available as permit parking in each zone polygon?
Additionally, if it is not yet published, please publish the number of permits granted, and / or the remaining capacity of each zone? Permits are granted on a six month period for permanent permits, and shorter periods for temporary / guest permits.