How long is a guinea pig year?

i just did the math, its or 1-09 year ratio, they live up to 5-7 years, humans usually live a natrual life of 78.7. according to the world development indicators. Therefore using the information given to me by guinealynx.info, we can safely assume every year, guinea pigs age around 13 years. we should celebrate their birthdays nearing every months end. ho-ray