How to check if a decimal is less than or equal to an integer?

I have the following code:

   public bool CheckArena()
    {
        if (Convert.ToDecimal(porcentajeArena.Text) >= 60 && Convert.ToDecimal(porcentajeArena.Text) <= 71)
        {
             error0.Text = "";
             return true;

        }
        else 
        {
            error0.Text = "Error. El campo Arena requiere de un valor entre 60% y 71%";
            }

For textbox I pass for example 63.5 but I throw the error saying that the value should be between 60 and 71.