John Graunt noted that in London over a 35-year period in the 17th century (1628–62), the birth sex ratio was 1.07; while Koreas historical records suggest a birth sex ratio of 1.13, based on 5 million births, in 1920s over a 10-year period. Other historical records from Asia too support James hypothesis. For example, Jiang et al. claim that the birth sex ratio in China was 116–121 over a 100-year period in the late 18th and early 19th centuries; in the 120–123 range in the early 20th century; falling to 112 in the 1930s.

Question: Was the birth sex ratio higher in 1628 or the 1920s?
Answer: 1920s

Question: Was the birth sex rate for China higher in the 18th century or the 1930s?
Answer: 18th century

Question: How many points did London's birth sex ratio differ from Korea's?
Answer: .06

Question: During which century was the birth sex ratio the highest in China?
Answer: early 20th century

Question: Did the birth sex ratio in China have a wider range in the 18th and 19th centuries or the early 20th century?
Answer: 18th and 19th centuries

Question: Which researchers are named that studied the Asian birth sex ratio in either Korea or China?
Answer: John Graunt