To find the yearly percent increase in population using the multiplier of 1.021, we can use the formula for percentage increase, which is:
\[ \text{Percentage Increase} = (\text{New Value} - \text{Old Value}) / \text{Old Value} \times 100% \]
In this case, the old value is the current population, and the new value after one year is given by multiplying the current population by 1.021.
Setting the old value as \( P \) (the current population):
- New Value = \( 1.021P \)
- Old Value = \( P \)
Now substitute into the percentage increase formula:
\[ \text{Percentage Increase} = \left( 1.021P - P \right) / P \times 100% \]
Simplifying this expression:
\[ = \left( 0.021P \right) / P \times 100% \]
The \( P \) cancels out:
\[ = 0.021 \times 100% \]
Calculating that gives:
\[ = 2.1% \]
Thus, the population increases by 2.1% per year.