When you buy most things, you only have to consider their price. Buying a home is different. Whether or not a home is affordable depends on a number of factors beyond the list price. Mortgage rates, for example. The mortgage rate you lock in when you purchase your home helps determine how much your monthly payment will be. Which means, it's important for home buyers to know where rates are and where they may be headed. In recent years, rates have been low. How low? Well, by historical standards, very low. According to Freddie Mac, rates in the 1970s ranged between 7 and 9 percent, before skyrocketing in the early 1980s, when they reached as high as 18 percent. And even though they calmed down in the 1990s and 2000s, they didn't fall below 5 percent until 2009, following the financial crisis and housing crash. Since then, rates have remained low. In fact, rates over the past few years have been lower than they've been at any point in the past 40 years – which is great news for anyone looking to refinance their loan or purchase a home.