Ok, time for some maths:
Total invested (so far after closed ICO): 10,254,276.64$ /85,000,000 ICN = 0.1206$
My investment: 5 BTC with 15% bonus + 10 BTC with no bonus = 5BTC + 0.75BTC (bonus) + 10 BTC = 15.75BTC = ~9,090.02 USD
In the estimated tokens to receive I have: 74,471.09 ICN so my final price per ICN will be 9,090.02 USD / 74,471.09 ICN = 0.1221$
I can't get how my price per ICN is bigger than the ICO price more so when part of the money was sent in a bonus period

Are your numbers adding up guys?
Best,
The bulk of your investment was made with no bonus, so this pushes the average price you paid higher than the $0.1206 ico price
On the contrary, someone who made the bulk of their investment during the 15% bonus period should have an average price paid lower than $0.1206
Why are you dividing the total sum raised by 85,000,000? the 15% of ownership that will be retained by the core dev team will come out of the total sum raised as well. So...divide the 10.25 mio by the total shares that will issued, 100 mio, and just remember 15% of those shares will stay with the dev team to compensate them for their work.
When investors are calculating ico price, they are looking at the average price per coin paid by the investor
Everyone's personal ico price will be slightly different, depending on which bonus period they invested in, but I would still consider the "official" ico price to be: (total funds invested by investors) ÷ (total coins issued to investors)
If you're looking at what the "official" starting market cap is, then it would be: [(total funds invested by investors) ÷ (total coins issued to investors)] × (total supply of coins)