Counterfactual
The Parallel Lives of Halley and Gertrude
In 43 girls, Halley found its level. 50 years earlier, Gertrude occupied that same statistical address.
1910–2025
Halley
Peak year
1986
Peak births
333
Latest count
43
Status
Rising
Peak generation
Millennial
1880–2025
Gertrude
Peak year
1917
Peak births
6,300
Latest count
17
Status
Endangered
Peak generation
Greatest Generation
In 43 girls, Halley found its level. 50 years earlier, Gertrude occupied that same address. One peaked in the Greatest Generation era; the other in the Millennial world. They never met. But the data remembers them both.