Visual Basic 6.0 help

I’m getting an error Run time error ‘6’ overflow.
Help me!! Tell me what’s wrong.

Private Sub cmdbutton_Click()
Dim population As Integer
Dim years As Integer
years = 0
population = 6000000
Do While population > 10000000
population = population * 0.014
years = years + 1
Loop
picWhen.Print “In”; years; “Population will be”; population;
End Sub