I'm in Taiwan this month to study Mandarin. During breaks, I'll be posting occasionally about the island nation's demographics, politics and (sticky) weather.

Like other East Asian democracies, such as South Korea and Japan, Taiwan has a rapidly aging population, posing demographic and economic challenges for policy makers.

One reason for the age increase is that Taiwan has among the lowest birth rates in the world. These charts highlight the trend. Here's the birth rate over time — with the United States, the world and East Asia for context:

With fewer births, the nation's median age has increased dramatically in the last three decades:

The aging change is particularly evident when you consider the relative proportion of specific age groups over time:

The data are a bit easier to digest when the age groups are grouped more broadly. The proportion of residents at age 65 or older, for example, has more than doubled since 1985.