Fertility fell fastest in the 1970s

Fertility fell fastest in the 1970s

Question. Which decades saw the fastest fertility declines?

• Encoding. Color encodes the first-to-last annualized change for each country-decade.
• Ordering. Country labels alphabetically; decade categories chronologically.
• Baseline. Zero is no first-to-last change. Each decade difference divides by nine elapsed years.
• Scale. Shared signed linear ramp; live strip scales may rescale under active filters.

What this design gives up

Within-decade reversals and endpoint levels are lost. Color is less precise than position for comparing close values.

A decade’s first and last observations are nine elapsed years apart, not ten. The annualized difference is linear, not a compound growth rate. The incomplete 2010s are deliberately excluded.