Verifying how much the local cultural event in Seattle effects the book checkout in the Seattle public library

SELECT
SUM(case When deweyClass > '741.49' and deweyClass < '741.6' then 1 else 0 end) as Comic,
SUM(case When deweyClass = '741.5952' then 1 else 0 end) as Japan,
SUM(case When deweyClass = '741.5973' then 1 else 0 end) as US

FROM
spl2.inraw

WHERE
DATE(cout) > '20121122'
AND DATE(cout) < '20121210'

LIMIT 100000

I set the four parameters; comic books (entire), American comic books, Japanese comic books, and Harry Potter related books. Four numbers has huge gaps in between, thus I tried to minimize the differentiation, and convey the changes visually by each months at the same time.

I change bar graph into same size taps, each taps include numbers of checkout or color indication of checkout number.

"Sakura-Con" is one of the biggest cosplay events in the US, it holds every spring. I expected that this event promotes the interest of residence in comic books, especially, Japanese comic books.
There were slight increase during the event. To make this result clear, I did compare comic books checkout to the Harry Potter books, the numbers showed me the Harry Potter book doesn't have specific patterns by each month, not like comic books.

I used Processing.

Control: There is a small button make checkout number visible.

Source Code + Data