Backup cleanup based on number of files rather than time

[sparky3245]

I have a large number of databases ranging greatly in size so keeping backups based on time is rather useless or requires micromanaging ever instance based on size. Is there a way to keep backups based on the number of full backups taken rather than simply saying "anything older than X gets deleted?" Currently we're using @Cleanuptime = 7 but our large databases are only getting 2 backups done within that time. I'd like to always have 5 full backups at any given time