Automatically Generate Sequential Number in Following Row

Hello all,

I need to create an Incident Log for the small police department for which I am employed.

It needs to automatically generate the next incident number in the next row when someone begins entering non-numerical values in the columns.

Our reports are 7 digit numbers (MMYY001, MMYY002, MMYY003, etc.)

The pic below shows an idea of what I need. Any help would be greatly appreciated.