I can't say regarding administrator passwords, but all the rest of the user accounts must change every 45 days. And I believe the history is 12 which bars a lot of reuse.

As far as just adding digits, sorry but that is lazy. I have not reused a password in over 15 years. I used to use an atlas to pick city names but our internal password policy changed. Today I use a password generator. As long as the password I choose fits the rules, great. It may take me a couple of login attempts to remember, but I am doing my part. In our company, policy states that YOU are responsible for anything on your desktop/laptop even though the company owns it all.