Deciphering an SIB encoding from Intel x86-64

Question

Here's a simple hello world file

 #include <stdio.h>            
 
 int main() {
     printf("hello, world\n");
     return 0;
 }

Here is the instruction to load the address of a string from the .rodata section into a register

lea rax, str.hello__world   ; hit0_0; 0x2004 ; "hello, world"

Because we are moving an address into a 64 bit register, we're using this form of LEA

REX.W + 8D /r | LEA r64,m | Store effective address for m in register r64

The hex dump of the instruction is:

- offset -   0 1  2 3  4 5  6 7  8 9  A B  C D  E F  0123456789ABCDEF
0x00001151  488d 05ac 0e00 0048 89c7 e8f0 feff ffb8  H......H........

So, the instructions look like:

REX.W: 0x48 ; 0x40 + the W bit is toggled
8D   : 0x8D ; 8D is the instruction itself
/r   : 0x05 ; I would be unable to get this without looking at the disassembly
            ; I'm guessing the offset is of wiki os dev
            

Here's the string for hello, world

- offset -   0 1  2 3  4 5  6 7  8 9  A B  C D  E F  0123456789ABCDEF
0x00002004  6865 6c6c 6f2c 2077 6f72 6c64 0000 0000  hello, world....

How do I calculate 0x2004 as the offset. I'm fairly sure the address begins at 0xac and the 0x05 is part of the offset