[AstroPy] Version No. for IRAF Software?

[Wayne Watson]

I'm writing a paper and wanted to cite IRAF. The editor provided this, but I need to provide the version no. Anyone know? Maybe it's just a date. 

Boroson, T., Tody, D. Shaw., R., Davis, L., De La Pens, M.,
Fitzpatrick, M., Seaman, R., Valdes, F., Zarate, N. (2009).
Image Reduction and Analysis Facility (IRAF) software, _*vx.x.x.x.*_
http://iraf.noao.edu/

-- 
           Wayne Watson (Watson Adventures, Prop., Nevada City, CA)

             (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time)
              Obz Site:  39° 15' 7" N, 121° 2' 32" W, 2700 feet  

           All the neutrons, and protons in the human body occupy
           a cube whose side is 5.52*10**-6 meters (tiny!). That
           adds up to a 150 pound person. It's not a surprise that
           we are mostly space. (Calculation by WTW)