Even with the Jiajing reforms to document migrant workers and merchants, by the late Ming era the government census still did not accurately reflect the enormous growth in population. Gazetteers across the empire noted this and made their own estimations of the overall population in the Ming, some guessing that it had doubled, tripled, or even grown fivefold since 1368. Fairbank estimates that the population was perhaps 160 million in the late Ming dynasty, while Brook estimates 175 million, and Ebrey states perhaps as large as 200 million. However, the Great Plague in late Ming Dynasty, a great epidemic that started in Shanxi Province in 1633, ravaged the densely populated areas along the Grand Canal; a gazetteer in northern Zhejiang noted more than half the population fell ill that year and that 90% of the local populace in one area was dead by 1642.