I think it's important to remember that people aren't becoming more LGBTQ+, it's that previous generations were so oppressed that coming out was impossible.
It's common to see these kinds of graphs used in some twisted ways. People are being allowed to be themselves. We have a historical president for graphs like this with left handedness. Once we stopped murdering, beating or ostracizing people for being left-handed, we saw "huge spikes" of people being left-handed.
Be yourself. Be loved. You aren't alone.