I don't see a clustered index on the table (but maybe I just missed it).

If you most often / always query the table based on YrMo, cluster the table on YrMo. Then you won't need all those nonclustered indexes that together likely more than double the size of the table.

You may very well want an need additional column(s) in the clustered index, to reduce the number of dup keys, but I can't tell what that/those column/s should be just from what I've seen so far. We'd have to look at least at index missing and index usage stats.