Around 2 years for the first 100, and another 2 years to 1000
Now 3100 subs, and growing with 1 or 2 pr. day.
But it did not come easy for me, I have made over 700 videos and have around 1500 views a day and totally over 3.000.000 view overall.
My channel is mostly about RC flying, so it is mostly men that watch my videos and there is also not that many RC pilots in the world, but I am happy for the views I all ready have got ..
When I started to upload consistently I was gaining about 1 - 2 every other week or so, sometimes one a month. When I made all my videos private and 'started over' (since they were pretty bad if I'm being honest) I have jumped up another 30ish over 3 months. I'm hoping to hit 100 soon!