Help with the stat sheets!

Hey I'm extremely new to esports, and following this stuff. I'm a little confused on what some of the abbreviations stand for. My main ones I can't find are FD,FB and AER. Can someone help thank you! I've looked online but I haven't found anything that makes sense.

If you're on desktop, you can hover over each of the legends to see what they mean.

FB = First Bloods (first kill in the round)
FD = First Deaths (first death in the round)
AER = Average Econ Rating (total average of econ ratings)