Clue from nature AD 1924

Scotland 1921 to 1937: sleepy sickness peaked in 1924 and did not follow the flu years

Registrar General for Scotland. Influenza deaths: 1921 1,330, 1922 3,706, 1923 531, 1924 2,490, 1925 1,246, 1926 1,421, 1927 2,026, 1928 961, 1929 3,435, 1930 696, 1931 1,270, 1932 1,724, 1933 2,027, 1934 602, 1935 1,459, 1936 659, 1937 2,693. Encephalitis lethargica deaths: 61, 45, 125, 181, 154, 169, 117, 114, 115, 122, 99, 79, 99, 80, 93, 95, 85. Year-to-year changes: same year r = -0.23, one year later r = -0.01. The two biggest flu years (1922, 1929) saw sleepy sickness fall or stay flat.

How it connects

This clue from nature argues against Sleepy sickness follows flu waves by about a year (Ravenholt and Foege) no one-year lag in Scotland

This clue from nature argues against Sleepy sickness and flu rise in the same years no same-year link in Scotland

This clue from nature is a clue for What caused encephalitis lethargica, the 'sleepy sickness' of 1917 to 1928?

This clue from nature we read it in Annual Reports of the Registrar General for Scotland, volumes 76 to 83 (1930 to 1937), Internet Archive scans. Values in el/scotland_1921_1937.csv

This clue from nature came from this step Added Scotland as a third country for sleepy sickness vs flu