I've seen that kittens grow skills with experience, but I couldn't find at what rate kittens gain experience.
How much XP does a kitten gain in a year?
The following is in the source:
var learnRatio = this.game.bld.getEffect("learnRatio"); //line 652 var skillRatio = 0.01 + 0.01 * learnRatio; //line 653 kitten.exp += skillRatio; //line 679
I think this is done each tick, so 5 times a second (iirc). So each second you gain at least 0.05 experience, depending on the
learnRatio is increased by the academy, 0.05 per academy. For example, 10 academies yield a
learnRatio of 0.5, and you'll get 5*(0.01 + 0.01 * 0.5) = 0.075 experience per second.
To answer your question (how much exp in a year): there are 400 days, and 10 ticks per ingame-day (source). That means that you'll get
4000 * (0.01 + 0.01 * learnRatio) experience
per in-game year.
In early game, without academies, it takes 100 ticks (5s) to gain 1XP, and a year yields 40XP.
It takes 100XP to for a kitten to get to Novice at a job (1.25% bonus), which is 2.5 ingame years, or 33 minutes. Left at it, she will reach Adequate after an additional decade (2h45 total) … and Master after 2 more centuries, i.e. 2d.
Later in the game, experience is gained twice as fast with 20 academies, thrice as fast with 40 academies, etc.