The age at which workers expect to retire has been continuing to rise in recent years, but reality might get in the way of an expectation, according to data from the Employee Benefits Research Institute.

Working longer has become a common response to concerns about retirement security, in particular following the financial downturn, as workers try to build up their retirement savings as well as their benefits from defined benefit programs—and effectively shorten the period during which they will have to live on those assets.

For example, in 1991, just 11 percent of workers expected to be on the job past age 65, but by 2015 that had risen to 36 percent. That trend has moderated somewhat in the last few years, though, with only 13 percent of workers reporting that in 2014 they had increased their previously expected retirement age, compared with 22 percent in 2013.

However, EBRI says that its data show that “a large percentage of retirees leave the workforce earlier than planned (50 percent in 2015). Many who retired earlier than planned did so because of a hardship, such as a health problem or disability (60 percent), though some state that they retired early because they could afford to do so (31 percent).”

While only 8 percent of workers say they plan to retire before age 60, in practice 36 percent actually do so; and while 26 percent say they plan to wait until at least age 70, only 6 percent actually work that long.

In addition, while 67 percent of workers say they plan to work for pay in retirement, just 23 percent actually do so.