Including sick days makes the calculation worse, not better. Sick days typically don't exist in Europe. If you're sick, you obviously just don't go to work. What's the point of infecting the whole office?
On average, workers in Europe take about 2 to 3 weeks off each year due to sickness in addition to their vacation. In fact, if you're sick during vacation, that doesn't count as vacation time, at least in some European countries.