How should a two-digit airport runway number be represented in XML?

Hi Folks,

"Runways, all runways, have a 2-digit number that represents the magnetic heading of the runway to the nearest 10 degrees. If the runway's heading is 265 — 274 degrees, then the runway number is 27 — always drop the last “0.” The opposite end of the runway is 180 degrees apart, so Runway 09 (90 degrees)."

How to represent a runway number in XML?

Specifically, how to represent Runway 09?

Like this:

<runwayNumber>09</runwayNumber>

Or like this:

<runwayNumber>9</runwayNumber>

One might argue that the former is better because it reflects how runways are actually numbered at airports - with exactly two digits.

On the other hand, one might argue that the latter is better because the value is an integer and the removal of the leading zero puts the integer into a normalized/standardized representation. You might further argue that XML is for machine processing and machines don't need the leading zero. If the runway number needs to be visually displayed to humans, then a zero can be prepended as desired.

What do you think? Which form is better?

/Roger