Doesn't this highly rely on your monitor and environment?
(http://i46.tinypic.com/2zz25w2.png)
I seem to remember I got a score between 10-20 on my old laptop but got a score lower than 10 a few months later when I got my current laptop. I seem to be improving as well, because I don't think I was this low last time.
I remember doing this about a year ago...Scored a perfect...found it again few months ago...yet another perfect... Though personally I'd say the third blue row was what I had the hardest time with and it's also the one that took me the longest time.
Let's try this again...
(http://i483.photobucket.com/albums/rr192/coolmannen05/1049.jpg)
And what I actually got ;)
Pretty proud of this as a photographer :D
(http://i483.photobucket.com/albums/rr192/coolmannen05/Bad.jpg)