Mon   Mean WWV (m**3) Std Deviation
 1    0.827054E+15    0.703187E+14
 2    0.780430E+15    0.616884E+14
 3    0.735305E+15    0.542617E+14
 4    0.711594E+15    0.454520E+14
 5    0.711262E+15    0.385920E+14
 6    0.723110E+15    0.342511E+14
 7    0.736610E+15    0.336923E+14
 8    0.753828E+15    0.390980E+14
 9    0.776765E+15    0.496744E+14
10    0.797831E+15    0.602802E+14
11    0.818824E+15    0.703648E+14
12    0.835657E+15    0.715560E+14