The Palm itself...

The Trunk of the Palm seedling

How long till it starts producing Split leaves?

I grew one years ago when I was on the Central Coast. Can't really remember the rate of growth except that it was pretty fast. Haven't been back to see if it's still there. Yours is looking quite good. Don't know when the leaves will start splitting but my guess would be it still has a bit of growing to do first.

When I had began growing it, it was at a very slow growing rate but ever since I added slow release fertiliser, it has gone nuts and grown absolutely fast. For example, the leaves on the palm have all approached in less that 6 months and that's including the time now that Australia is in Winter which means that palms are Slow Growing or No Growing in Winter. All seems good, the Palm is healthy and doing great.
Ps- I love palms: I have 15 different species growing in by Backyard - MOSTLY IN POTS!!

Should I warn you that it's addictive, or is it too late? I'm an addict, given up all hope of rehabilitation, LOL. I have 62 different named species, 3 unnamed, and about 10 other species that are as yet unsprouted seeds (but still hoping). The obsession never ends, I still don't have enough.

I totally agree. I go to the Nursery and every time I come back with a Palm. My parents get angry with me every time. I got species such as Cocos, Bangalow, Majestics, Dwarf Dates, Golden Canes, Sago (Cycad) and this is just to name a few. I am definitely a Palm addict and my family think I'm weird (they hate palms but I love them!!)

If by splitting you mean fanning out since it already appears to be splitting, then you still have a LOT of growing ahead of you.

My mexican fan palm is in it's "I'm gonna grow and you can't stop me!!!" stage. That's what I call the insanely fast growing stage. It's only a year old in August. I saw split leaves as early as last month (June 2013). So, for a mexican fan palm, in a pot you'd see split leaves in about 10 months at average with great care. But Fan fronds on my mexican fan palm still have until maybe next Christmas or the Christmas after that. We'll see.

I would assume that you should expect fan fronds in the next 2-3 years on your palm.

And as for TropicalBreezent:

You shouldn't joke about being addicted to palm trees. It's very serious! I wake up every morning with a palm tree in my face. When I open my eyes, all I hear is "BOO!!!" Like the blasted thing is gonna jump at me!!!

JK. I love palm trees so much that I want to move to Florida just to see a palm tree around every corner. They are natural legal narcotics that the government cannot arrest you for possessing. They make me feel relaxed when I care for them. Long live Palm Trees!!! :-)