Note: This calendar view maps the number of captures of https://accounts.google.com/ServiceLogin?service=youtube&uilel=3&continue=https%3A%2F%2Fwww.youtube.com%2Fsignin%3Faction_handle_signin%3Dtrue%26next%3D%252Fsignin_passive%26hl%3Den%26feature%3Dpassive%26app%3Ddesktop&hl=en&passive=true, not how many times the site was actually updated.
Look Up URL in general Internet Archive web collection.