It isn't really clear what he needs it for, I'm not sure if he needs a text result or not, but the formula will show the amortization for each entry regardless of how old it is. If you create fields like you have suggested, you would not be able to use or view the details after a year (unless you create infinite fields). This way you have the amortization listed by year in one field regardless of how old it is. You would be able to report on this data by formula if required. You could use it in conjunction with your method if you are wanting more detailed reports of the previous/current/next years too.
Edit:
You could also just change the field type and return the figure that is calculated and leave off the year to use this as a number for reports in a 'current year' or 'next year' field
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Luke McInnes
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