Answering another Seattle budget question: how much have we spent on housing?

I previously looked at how much the city of Seattle has planned to spend in total every year since 2005 – divided by Seattle populated and adjusted for inflation to 2017 dollars. Another question is to ask how different departments spending has changed in that time frame. The big topic right now is homelessness and housing. I pulled the adopted expenditures for three departments:

You can review my quickly assembled spreadsheet if you like. This graph seems to tell a pretty big story.

Graph of expenditures from spreadsheet linked previously

I look at this graph and note:

As with the previous post, I will happily take comments, corrections or suggestions. This is just me doing what seems obvious and straightforward to start to understand the "shape" of the problem.