This graphic illustrates a time series of how old women are when they give birth. The trend shown - that women are having babies later in life - is well established, but this visualization really emphasizes how the changes have occurred. Using data spanning 1975-2010, I plotted 5 year increments, then added vectors to shown the change in birth rate from 1975 to 2010. Clearly, fewer teens and women in their early 20s are giving birth (down arrows). Instead, they are choosing to wait until their 30s (up arrows). The middle age bin (25-29 range) shows virtually no difference between 1975 and 2010; the subtraction yields +0.1 births per 1,000 women in that age range.