iCloud backup for iPhone 6 keeps increasing in size
Recently the iCloud backup for my iPhone 6 began increasing in size with each new backup. Day1 was 8mb, day2 - 1gb, day3 - 1.8gb. This will continue until my 5gb of iCloud storage is used up and then I delete the backup and start again. I am not adding anything significant to my iPhone to account for this daily growth. My estimated next backup size shows 127mb of doc and data and 260mb of Apps for a total of 387mb. I do not backup photos. How can I determine what is causing the backup to grow daily and be over 4gb? It seems like the prior backup is not deleting from iCloud properly.
iPhone 6 - Ver 9.3.2(13F69)
iPhone 6, iOS 9.3.2