I guess the difference is because GDP has generally been growing much faster than the population. I think both figures are useful to look at. The spending vs GDP plot tells you something about government frugality (or lack thereof) in the context of welfare spending, while the per capita plot tells you about the benefits to recipients. So it's possible for the government to actually spend less (over time) as a fraction of GDP, and still have more money available for individuals to make the best of bad times. That sounds to me like the way to go, at least for the next few years.