Definitely, you can see some lines in the top left zigzagging back left, which would not be possible if each was a function of the x-axis. In fact, both axes are a function of the hidden z-axis, which is time and comes in discrete yearly steps, the latest of which (2021) is highlighted.
My guess is that this was a gif at some point and the line is historical data
Definitely, you can see some lines in the top left zigzagging back left, which would not be possible if each was a function of the x-axis. In fact, both axes are a function of the hidden z-axis, which is time and comes in discrete yearly steps, the latest of which (2021) is highlighted.