Environment: 7.2.4 to 7.4 (not applicable to 7.5 and later)
To find out how many Analyst licences you have available and how many are used there is an object within Service Desk you can query against.
The object is within the Sytem module called Licence Audit Item. New records are created periodically (at least once a day) with an audit of the number of Analyst and End Users allowed by your licence and how many are current used. Create a query against this object within Console and sort it by the Date attribute descending to see the latest audits at the top of the results.
Note that while there is a number attached to the End User licence this is not enforced.