Add a Scoreboard Stat for Getting any Achievement (stat.achievementGet)

I would like to reward the players on my vanilla Minecraft server with something whenever they get a new achievement, and I would rather not add a scoreboard for EVERY SINGLE ACHIEVEMENT STAT in the game. That's too many command blocks, too much work. And new achievements are always being added all the time.

Instead, just add a new scoreboard stat for it. Something like "stat.achievementGet". This stat would only increase if it's the FIRST time that you're getting any one achievement.

Thank you!