All you need do, if this poll is intended to reveal the distribution of "Sun in Elements" is look at birth statistics by dates, and you will get a much better statistical picture of the distribution among the general population.
Assuming the Sun travels through the circle of the ecliptic at an even speed (it doesn't, but it's close -- it moves faster while in Aquarius than it does while in Leo), and that births are evenly distributed throughout the year (they're not; the figures for 2010 are in the table below), then we would expect an even distribution by sign and by element.
Most Common Birth Month Statistics (Source:
http://www.statisticbrain.com/birth-month-statistics/ : from the CDC).
Total number of US births in 2010 = 4,000,279
August 362,798
September 350,711
July 347,934
October 347,354
June 336,251
March 335,786
December 335,111
May 334,437
November 330,832
January 319,297
April 308,809
February 299,235
this table shows that 9.077% of all US births occur in August (Fire and Earth) while only 7.483% of births occur in February (there are about 18% more births in August than in February, widely approaching a ratio of 5:4). This means there is a lot of Hanky-panky going on in November and December.
The average number of births per month (4,000,000/12) is 333,333.
By adding February, June and October we can get a rough total for Air (982840), and thus for each of the elements. We see that Air is under-represented [the total should be 1000000.]
Yes, signs and months are offset, but this gives us a ballpark picture of the distribution.