I don't have those statistics. If you're asking if people are using their sick leave as vacation days, that would be an inappropriate use of the sick leave. The sick leave is to be used by employees when they need to be absent for medical reasons.
We must take the population into consideration. People who retire are typically toward the end of their career and more aged. With age comes all sorts of problems, and consequently it would be unfair to equate the use of the sick days solely with the fact that they are retiring. In many instances we see people who actually have heart attacks while they're at the office, or they leave the office and have a heart attack, and are off for quite a number or days and then decide that they don't have the strength to come back and they then retire.
It's often misinterpreted as being a use of their sick leave before they retire, but in many instances where we have older employees who have worked hard, been under extremely stressful situations for years—for long periods of time—it has an impact on the body.