Averages as well as you say are useless. You know this, so I don’t know why you bring averages up. I specifically mentioned the most common salary, not the average or the mean, which are completely skewed.
You should also research the salaries of other people who also have a “bachelor’s degree” as you call it. That is, if they get employment and don’t have to emigrate.
That looks like probably median _income_ (ie would include people on social welfare, pensions, part-time workers). Data seems a bit all over the place, but most estimates of median full-time seem to be around 2000eur/month. Spanish min wage is 1184/month for a full-timer, so it's virtually impossible that median full-time income would be only 75 eur more than that.
You should also research the salaries of other people who also have a “bachelor’s degree” as you call it. That is, if they get employment and don’t have to emigrate.