Tаble defining vаlues оf functiоn I(t). t=yeаrs since 1980 0 5 10 15 20 25 30 I=annual incоme $23109 $23116 $25284 $26594 $30719 $30350 $28838 The regression line is (Y=264.93X+22884.64). Explain in practical terms the meaning of the slope of this regression equation.