Complex sentence: The war began to adversely affect the economy in late 1917; the Company threatened petrol rationing in November 1917, and in early 1918 it raised the colonial income tax to help balance the books.
Split into simpler sentences: The war began to adversely affect the economy in late 1917. The Company threatened petrol rationing in November 1917, and in early 1918 it raised the colonial income tax to help balance the books.