Why do we live longer now than we did 100 years ago?

See below. There is a concept called compression of mortality. In early 1900's people died at early age from infectious diseases until 1940's when penicillin discovered and developed resulting less death. The overall death from the cardiovascular disease began to reduce in 1970's with help of medications and better treatments. More medication/prevention of care helped to reduce overall death in 1990's.