Normalize repeated measurement (calculate ratio) using formula

Hello,

My experiment has a large number of subjects. I recorded the occurrence of a specific behavior for each subject. Then for each subject, I want to normalize the value of each occurrence to the fist one (the ratio). I made formulas as shown below (I separate the numerator and denominator to make it clear), but the denominator has a problem. I can see why it gives "FALSE" results but I couldn't come with a solution.

A B C D E F G
1 ID No value ratio numerator denominator
2 A 1 0.79 =0.79/0.79 0.79 0.79
3 A 2 1.32 =1.32/0.79 1.32 FALSE
4 A 3 1.30 =1.30/0.79 1.30 FALSE
5 A 4 1.23 =1.23/0.79 1.23 FALSE
6 B 1 0.83 =0.83/0.83 0.83 0.83
7 B 2 1.20 =1.20/0.83 1.20 FALSE
8 C 1 0.92 =0.92/0.92 0.92 0.92
9 C 2 1.48 =1.48/0.92 1.48 FALSE
10 C 3 1.50 =1.50/0.92 1.50 FALSE

F10 (numerator)=IF(ISNUMBER($D$2:$D$10),IF($B$2:$B$10=$B10,$D10))
G10 (denominator)=IF(ISNUMBER($D$2:$D$10),IF($B$2:$B$10=$B10,IF($C$2:$C$10=1,$D$2:$D$10)))

Really appreciate if anyone can give me some help.