Could I use the expression "twenty years later" at the end of a sentence? The context is a description of a graph and I want to write that those figures fell dramatically twenty years later. Thank you!
... though, of course, more context would help. I you are simply interpreting a graph, tacking on 'twenty years later' will always be possible, but doing something else with those words may be a better bet: 'As the graph shows, sales increased steadily throughout the sixties; twenty years later, though, there was a sharp decline'.