Hi. I've gotten 100% and 1%. But I would think you should have gotten some. Shipping is hard on eggs. Here's some of the stuff that makes a difference:
Try to not buy eggs if you live at sea level and the seller lives in the mountains. I've known hatcheries to supply additional O2 to their incubators. It has to do with atmospheric pressure.
Virilty of the rooster. Shipping hardiness of the breed. If you buy alot of eggs, crack one open and see if it's fertile.
I leave my eggs on the counter slanted pointy side down for a full day or day and a half.
I have 2 thermometers, and at times, 2 hygrometers. One thermometer lays on top of the eggs or at the same height.
A friend of mine used to take a thermometer and a hygrometer out to her hen sitting on eggs. The results were the humidity was less than 30% for 18 days, then above 66% for the last 3. So I keep my eggs eggs 25-30% humidity for 18 days, and my goal for the last 3 days is 66-70%.
I turn my eggs 2-3 times a day, and move the outer ones to the middle etc, once a day. I keep my eggs as close to 100-100.4 degrees as humanly possible. Sometimes I have to cover half the bator or add a lamp pointed at the incubator to stablize the air. Not too close.
These things have improved my hatches 100%.
Keep track of when they quit, or if they even start. If they don't start by day 7, (candling) crack it open and see if it's fertile.