Use the model below to estimate the average annual growth rate of a certain country's population for 1950, 1988, and 2010, where x is the number of years after 1900.
y = -0.0000084x^3 + 0.00194x^2 -0.196x + 7.819
The estimated average annual growth rate of the country's population for 1950 is enter your response here ___________