Really? Is there a disproportionately high number of older people in the state? I would have assumed it's similar to the other states.
First, the entire country is ageing and more and more baby boomers will be retiring. By 2030, there will be twice as many retirees [70 million] as there are today.
Second, retirees are heading to places with lower taxes and better weather. They are free from the shackles of having to live where their job is.
There is a difference within the US among states on the median age of the population. Maine is the oldest and Utah the youngest. NJ is the 15th oldest. Median Age of the Total Population: 2003