For years we’ve heard that Americans are living longer. Since 1960, the average life span has increased by seven and a half years. But experts say living longer shouldn’t be where we focus. We need to think about our health span. Our health span is the number of years that we spend in good health. And this will not surprise you, but that number is shrinking. Even though medicine has gotten better at keeping sick people alive, we’re all living longer with chronic ailments. That is creating issues for the healthcare industry and our wallet…