Well. I was actually really surprised when I looked up the date on the first one.
Turns out I've only been drawing humans - and I started with human females - for three years.
So I found 3 examples of me drawings.
2016: Drawn around November for a fan fiction called StarDust. It was the humanized version of the main character, Silverpaw. My vague sense that light existed is amusing. The twig/bird arms are better in my opinion. This was around my first serious attempt to draw a human.
Brightspirit of WindClan created her.
2017: Drawn in December! So I figured it counted as being close to the middle as my 2016-2019 stretch could get. That's Dawny's character. Er ... not much has changed? Off hand I can notice that my lines are a bit sketchy, but I wasn't actually aiming for neat lines when I was drawing it. And then the shading could be tweaked a little. Even my head shapes have stayed about the same. Clothing wrinkles have gotten slightly better.
2019: Drawn last month (Feb). A pen doodle, since I neither have a full on effort picture nor one done in pencil. Lady Loki doodled without references and I believe only Cloverleaf and my RP partner have seen this but I could be wrong.
I generally did a 'bah, what light source?' on this one as well. Hair Is more detailed instead of sketchy and I was playing around by stealing Iceclaw's style of nose/face shape. Clothing wrinkles were intentionally supposed to show oddly shaped sleeves and tighter dress/looser skirt-part. Sorta succeeded.
And that's three years of human art.