[kabouseng]

Well actually close. If you have 40 years of productive work in you (20 years to 60 then retirement), then yes every 10 years 25% of the workforce does retire.

But I would guess that those 10% of students are heavily skewed to students in their final year of study. Second point is that not all undergraduate courses are 4 years, some are 3 years, so probably closer to 7.5% of students on SO graduate every year.

Which might indicate that the software development field is growing in terms of people active in the field.

*Then again software development is a young persons game, so "retirement" out of the industry might be higher since a lot of people will retire to other fields / management positions.