Graph labeling is deeply ingrained, a habit formed in high school days where points were docked for lack of X and Y axis label with units, and a graph title. When I see graphs in popular magazines lacking these 5 elements, I become irate - what kind of useless graph is this! and ignore any conclusions drawn from the graph. I should point out my sample size is about 168, and so I think that should I apply stats, we could get some significant results from the data here.
I go through a LOT of batteries with my camera flash (Canon 430 EX). All is fine when the batteries are spanking new. With tot and baby pics, it's all about timing and being opportunistic, so if the flash doesn't go off exactly when I need it (which maybe once a second) - I change out the batteries. Sure the flash also needs to time to cycle up for the next pop of light, but pooped out batteries are slower at providing energy needed. Rechargeable batteries unfortunately are too slow/ un-powerful my flash purposes; won't go into boring theories of Why.
I do know that the batteries have juice left, so for the last over 2 years I've been accumulating post-flash batteries in the Batteries For Wii Remote drawer. My husband, on a sudden inspiration of geekiness, decided to use his voltage meter to see what voltage remained on all of the batteries. A full battery is 1.6 volts; a useless battery (the Wii remote complains at) 0.8 to 1.0 volts. He asked me to hypothesize the median voltage (that's the highest bar chart bar, for you non stat peeps) and I guessed a Normal Distribution (ie bell curve), making 1.3 the median, and Voila, the distribution is a slightly skewed Normal curve. (Please note; the batteries are double stacked; two layers).
From this I can see that batteries are pretty useless for Flash under 1.4 volts, and that I can probably squeeze some more flash pops out of the 1.5 to 1.6 batches. 1.3 to 1.4 batteries can be used to keep Wii remotes happy; 1.1 to 1.2 might be good for clocks, and 1.0 and under can be (properly) disposed.
Thus my conclusion and scientific recommendation is that We Need to Play More Wii.