Sourdough

In the old days, the percentage of protein was listed on a package of flour. I consider 9% to 15% too be very good bread flour.

Today, from what I can see is that percentage is not listed anymore but is given in grams.

So, I have a 5 pound bag of flour that is listed as 4 grams of protein in the the mix.

What is the percent of protein?

Thanks!