I have no clue why the traffic going down all of a sudde

Hello Friends,

I am doing SEO for a website which is goo.gl/UVwuPw. I have submitted website
in Google search Console.Out of 9 URLS, 7 URLS got indexed. I have noticed drop in traffic( impressions going down) since 13th september 2017. I have no clue why the traffic going down all of a sudden. It would be of much help if anyone could suggest me what to do on this and how to increase traffic.

thanks