In the past few years, we have always been able to edit the Auto-Number Field Tray to match with the beginning of the new year. For example, I was able to change the Auto-number settings to 16-00001 on the Opportunities page. This year however, I am having great difficulty setting it to 17-00001. I keep getting notified that since the number I have in is a lesser value it can create duplicate opportunities. I do not want to update pre-existing records and I would like to ensure that our company can start the new year with a clean 5 digit number. How come this has changed within in the year? Can anyone advise?? I have contacted ZOHO help as well as my IT company and no one really has given me an answer. 

Thanks!