Read this: On the uneven bars, the gymnast performs a routine on two horizontal bars set at different heights. These bars are made of fiberglass covered in wood laminate, to prevent them from breaking. In the past, bars were made of wood, but the bars were prone to breaking, providing an incentive to switch to newer technologies. The width and height of the bars may be adjusted. In the past, the uneven parallel bars were closer together. They've been moved increasingly further apart, allowing gymnasts to perform swinging, circling, transitional, and release moves, that may pass over, under, and between the two bars. At the Elite level, movements must pass through the handstand. Gymnasts often mount the Uneven Bars using a springboard, or a small mat. Chalk and grips (a leather strip with holes for fingers to protect hands and improve performance) may be used while doing this event. The chalk helps take the moisture out of gymnast's hands to decrease friction and prevent rips (tears to the skin of the hands), dowel grips help gymnasts grip the bar.
Now answer this question, if there is an answer (If it cannot be answered, return "unanswerable"): How have the bars changed over the years?
They've been moved increasingly further apart