Then maybe there isn't a real difference. See statistical significance.
In the future, if you are making a graph like this, and the differences are so small that they don't show up when your y-axis starts at 0, they probably aren't important enough to talk about.
If you've taken a stats class, you probably know there are times when small differences are meaningful. Any time you're analyzing your own data, though, these differences are rarely worth even considering. Taking a survey and analyzing the resulting data is very hard. There are countless nuances that can affect your results, both mathematical and psychological. Look at political polling - even the people who do it for a living regularly get things wrong.
That's the point: the differences are small.