One problem with your conclusion is that it misses the fact that there is more than one convention per circuit, per year, where people get baptized. You are not taking into account the people baptized during the same year, in the same circuit, but in a different convention. However, this error may be offset by the fact that not all attendees are publishers and that some missing in the convention have faded or disfellowshipped.
Interestingly, your figures reflect the statistics of the Pew Research of 2014, in the U.S., that revealed that the ratio of men to women in JW land is almost 1:2 or 1/2