Relationship between the age of the universe and its density.?

Well im no scientist so dont quote me on this,just my thoughts on the matter(lol). The thicker the universe is, or dense, the more things that are from the original point of origin in the mix.The Universe may be slowing down but it is still expanding at a very high rate.Its like kicking dirt in slow mow.As you kick the dirt a large amount of the dirt fly's up, but the further it goes the thinner it gets.So to see the age of the Universe(in section's) you must envision the Big Bang, and then look to its density and overall build.