Nicely selected stat.
"Household" income going up merely means that there are more workers/household, and the demographics will prove it.
Babyboomers' chilluns are now teenaged and getting part-time jobs.
indeed, that's how people are affording to buy houses here on long island - 3 or 4 wage earners per household now.
If you can find Census data through 2003 for individual median incomes, you're a more assiduous researcher than I am.
I can only find data up through 2001.
Looks like normal business cycle stuff to me.