Reliably duplicate custom IR remote control with ATTiny85
The exact duration of the pulses don't matter much. In your example, you see that in all three recorded samples that's 

about 14000 (about 9400); about 1200 (about 600); about 1200 (about 600) etc.


What matters is that nowhere you have pulses of about 900 : in other words if the receiver detects a 672 pulse it will know that it's definitely a 600, not a 1200.

So if you send exactly those values, the receiver will recognize it.