Income Mobility

Here is a link to the earnings mobility of US households over a seven year period. I thought it was interesting to note that the majority remained in their current quintile over the period recorded, but that there was movement in all directions (up and down). The bell curve is evident, but I would like to know who went from the lowest to the highest (residents in medicine? Recent college grads?) and vice versa (retiring executives?).

Swimming, swimming, keep on swimming...