IS Your ISP tracking everything you do?

I am a Kenyan and we have many ISPs one of which I have worked with as an System Engineer. The questions that should bother the corporate companies and individual since all of us has to get online through an Internet Service Provider is whether the ISP is tracking everything you do online?

This may not be something most people are thinking about, but for those constantly worried about digital privacy, it is a  must concern, since, if true, everyone would be subject to tracking because we almost all have to get online through an Internet service provider as I have already stated.

Your ISP "is your path way to the worldwide computer network known as the Internet,"  Every page request you make and every e-mail you send must travel through your ISP's routers first. It would seem, therefore, that your ISP has the power to scan and save every piece of data that flows through its system."

But before you get worried, "The truth is that it does have the power”. Fortunately there may be some hindrances’ in terms of organizing every bit of information that passes though its routers. This calls for more investment in labor and infrastructure. So most probably in my view, they doesn’t hold all the data but they hold some data for a moment of which they may interfere with you privacy. 
For Example of details that are held for some moments is emails. If your mail server is offline the ISP servers holds the emails until the your mail comes online.

Do you think Your ISP track what you are doing online?