You'll need to add a clause where a certain share of the stock (I assume you own 100%) to be bought back by the company each year. The percentage will take in account of the risk since the company will keep on growing. In any case, you'll have to have to have a business attorney to write the term sheet due to legal wording and general liabilities. Your best bet is to find a good template and have the attorney modify it - that way you save the attorney's time and your money.