Mark my words, I'm going to prove that graph wrong!

After googling some researches it seems that rem sleep does decrease as you grow older, but most researched conclude a decrease of 10~25% and that last graph shows a decrease of more than 50%.
But I guess it will vary a lot for each person, because somebody who won the lottery and who will never have to work again will probably get more REM sleep than a Chinese worker at Foxconn. Same goes for people in countries that have a siesta.