Back in the 1990s, I maintained a "Population of Space" page which showed exactly this. To my knowledge, nothing like it exists anymore, which is a shame. I occ

Back in the 1990s, I maintained a "Population of Space" page which showed exactly this. To my knowledge, nothing like it exists anymore, which is a shame. I occasionally think about recreating it, just as soon as the day job leaves me some time... [Edit: oh cool, there's something kinda like it in the sibling comment! Mine was different, showing a less granular graph wth the population averaged out on a yearly basis. But it also included a table of all missions and notable events affecting trends in the population of space.]