Mon   Mean WWV (m**3) Std Deviation
 1    0.252883E+16    0.542639E+14
 2    0.249438E+16    0.510412E+14
 3    0.246166E+16    0.558919E+14
 4    0.242816E+16    0.622138E+14
 5    0.239964E+16    0.701321E+14
 6    0.238141E+16    0.762375E+14
 7    0.237649E+16    0.779691E+14
 8    0.239409E+16    0.779465E+14
 9    0.243311E+16    0.772844E+14
10    0.248187E+16    0.758559E+14
11    0.252695E+16    0.711830E+14
12    0.254493E+16    0.608890E+14