Not concidering difficulty changes and next years block reward halving it would take you an average of approx. 8 years to find 1 block.
You should be assured to find one in 8 years,
Its a coin flip 50/50 that you find one in 4 years
1 in 4 shot that you find it in 2 years
1 in 8 that you find one in a year.
Feeling lucky?
When setting up a vanity wallet address that I wanted to be 1bitcoinxxxxx I think it told me it would take a year or some sort,
It took a month.
I was lucky