user88676: I have an Antminer S9 ASIC miner , and I have visited this , but I want to know how difficulty may impact my profitability in the future. I would also like to estimate break even costs. 

user5406: 
Source: http://bitcoin.sipa.be/speed-lin.png
The difficulty growth has been slowing down over the years, but in the last year it still has about quintupled.

Source: http://bitcoin.sipa.be/growth-10k.png
The general formula for calculating profitability is elaborated on How much Bitcoin will I mine right now with hardware X?.

88676: <p>I have an Antminer S9 ASIC miner , and I have visited <a href="https://antminerprofitability.com/antminer-s9-profitability/" rel="nofollow noreferrer">this</a> , but I want to know how difficulty may impact my profitability in the future. I would also like to estimate break even costs. </p>
 5406: <p><a href="https://i.stack.imgur.com/FMdeU.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/FMdeU.png" alt="enter image description here"></a></p>

<p><sup>Source: <a href="http://bitcoin.sipa.be/speed-lin.png" rel="nofollow noreferrer">http://bitcoin.sipa.be/speed-lin.png</a></sup></p>

<p>The difficulty growth has been slowing down over the years, but in the last year it still has about quintupled.</p>

<p><a href="https://i.stack.imgur.com/S6yIi.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/S6yIi.png" alt="enter image description here"></a></p>

<p><sup>Source: <a href="http://bitcoin.sipa.be/growth-10k.png" rel="nofollow noreferrer">http://bitcoin.sipa.be/growth-10k.png</a></sup></p>

<p>The general formula for calculating profitability is elaborated on <a href="https://bitcoin.stackexchange.com/q/118/5406">How much Bitcoin will I mine right now with hardware X?</a>.</p>
