I try to write some clear code to refactor C# if else_if statements [closed]

**THIS METHOD TAKES COURSE AND EXP AND GIVES BACK RATING ** USER ENTERS HIGH QUALIFICATION AND EXP AND IT GIVIES RATING PLEASE HELP ME WITH THIS

 public double Rating(string HQ, int exp)
    {
        double rating = 0;
        if (HQ == "BTECH" && exp == 3 || exp == 4 || exp == 5)
        {
            rating = 3;
        }
        else if (HQ == "MTECH" && exp == 3 || exp == 4 || exp == 5)
        {
            rating = 4;
        }
        else if (HQ == "BCA" && exp == 3 || exp == 4 || exp == 5)
        {
            rating = 2;
        }
        else if (HQ == "MCA" && exp == 3 || exp == 4 || exp == 5)
        {
            rating = 3;
        }
        else if (HQ == "MSC" && exp == 3 || exp == 4 || exp == 5)
        {
            rating = 3.5;
        }
        else if (HQ == "BTECH" && exp > 5)
        {
            rating = 6;
        }
        else if (HQ == "MTECH" && exp > 5)
        {
            rating = 8;
        }
        else if (HQ == "BCA" && exp > 5)
        {
            rating = 4;
        }
        else if (HQ == "MCA" && exp > 5)
        {
            rating = 6;
        }
        else if (HQ == "MTECH" && exp > 5)
        {
            rating = 8;
        }
        else if (HQ == "MSC" && exp > 5)
        {
            rating = 7;
        }
        else if (HQ == "PHD" && exp > 5)
        {
            rating = 9;
        }
        return rating;
    }

Please check out my CODE I do not like all the above if-else statements and believe that there is a cleaner way to write this. How could I refactor it?