This schema is designed to record the diff of the sys.dm_exec_query_stats at regular intervals in order to determine which are the most expensive queries over time. It is meant as a subsitute for where you cannot use query store (e.g. pre-sql2017 or on a secondary replica)
Ideally this would be put into its own db so there is not a clash on schema.
Create all the objects using EITHER the sql2012 version or the sql2017 version depending on your enviroment
Put the procedure [Monitor].[LoadQueryStats] into a job to record the querystats data at regular intervals.
You can use the view Monitor.Querystats_view to see the data you have collected.
Execution count is not completely accurate.