The numbers from left or right are approximate sales rank and estimated total copies ordered.

Numbers are taken from ICV2 and Comic Book Resources

Feb. 2003 Promethea #25 - 109 13.41 16,775
Dec. 2002 Promethea #24 - 114 111 15.74 17,222
Oct. 2002 Promethea #23 - 108 80 15.65 17,694 - note more expensive $3.50
Sep. 2002 Promethea #22 ranked at #127 on the Diamond Top 300 list, with sales of 18,050
June 2002 Promethea #21 114 18,109
April 2002 Promethea #20 103 19,323
Feb. 2002 Promethea #19 85 19,847
Dec. 2001 Promethea #18 92 20,758
Oct. 2001 Promethea #17 110 21,246
Aug. 2001 Promethea #16 88 22,035
June 2001 Promethea #15 79 22,643
April 2001 Promethea #14 73 22,420

Note about Issue #23:
From left to right, that's quantity rank out of 300 comics, dollar amount out of 300 comics and ratio of Promethea comics ordered to Batman comics ordered (a figure inserted to help retailers order unknown titles, I guess).

JHW3's reaction to these figures
"interesting info. i do think that sales will start to improve over this year and into next year, hopefully. i order a copy of every issue for myself even though i get copies free from wildstorm. i do this because if i'm not willing to buy my own material i can't expect anyone else to. i also find it interesting that we seem to be selling less the more we seem to garner critical attention and acclaim. go figure."
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and a later reaction from JHW3
"the sales figure slow down is very disappointing but not completely unexpected. alan isn't at all surprised by this. he knew that we would be moving into some very unconventional storytelling (for superhero comics anyway). so its not too surprising that we've faced some losses. but alan and i are quite confident that over the years after all of collections have been in print for awhile that some them will come back to it and see something in it that will proove to have value. its always tends to be that way with material that pushes the boundries. time will tell. and thanks to all of you who have been loyal and been willing to go on this journey that isn't met with traditional plot points. and yes there is still a plot here to this series. its just not in the conventional sense. you can get that elsewhere all of the time. so from my own fan perspective i think its very refreshing to have something like promethea to be around and i hope to see more unusual comics in the future."