for this kind of task I would use a crawler - like Screaming Frog for example.
However, it´s possible to get an estimate for the total number of pages in a given year just by looking at the Pages report (however, you should exclude repeating page name patterns such as search results pages or similar and just try to clean up the entries the best way you can) - then just go to the last page of the report and look at the index number in front of the last page name listed.
As to the number of new pages published in the last year - unless you are collecting the publication date of a page in a variable, it could be a tedious task in Adobe Analytics. Again you could use the Pages report - compare last year with the current year and sort by Change (ascending to descending) - obviously the pages with the highest change had no or very little Visits last year - therefore there were either published or heavily promoted this year. This could give you an idea of the aprox number of new pages published this year.