The island-nation of Zephyrus is a highly globalised economy with a significant reliance on international trade. In the circular flow of income, leakages such as import spending play a key role in determining the national income multiplier. Between 2022 and 2023, the average annual household disposable income in Zephyrus rose from SGD 55,000 to SGD 61,000, while the average household annual expenditure on imported goods and services increased from SGD 13,200 to SGD 15,120.
Using the information from the stimulus material, calculate the marginal propensity to import (MPM) for Zephyrus households between 2022 and 2023.