Dividing merged cell in two different sheet

I have two different excel sheet with merged value. Suppose, column A of sheet 1 has merged row (A2:A5), (A6: A10) and so on and column B of sheet 2 has merged row (D2:D5), (D6:D15), (D16:D20) etc, . I am trying to divide the value of column 1 by column 2 like (A2:A5)/(D2:D5), (A6: A10)/(D6:D15),.... , but I am getting wrong value for second division. Numerator value is changing but the denominator remains same. Sorry , yy sentence must be confusing. This is what I am getting:

(A2:A5)/(D2:D5)
(A6: A10)/(D2:D5)

But actually I should get
(A2:A5)/(D2:D5)
(A6: A10)/(D6:D15)

Please help.

Anjani

I have attached sample files