Chicago Property Tax Increase

[Alexander Chavez]

Currently living in a two flat in the Avondale neighborhood of Chicago.  I purchased in 2013 for $175K. My property got an assessment of $315K by cook county (increased from $250K to $315K in 2015).  Last year I paid about $5K in taxes.  I have a few questions

1. Should I appeal the assessment amount, if so how do I go about it?

2. What will the be the tax increase I can expect for 2016 and when will this become effective?