I looked at the chart for percent of teachers working on a given day (orange and gray one). The orange alone gives 9.5 hours per day. That alone is more than 40 hours per week.
Number 6. Sorry, the color description was completely useless.
Edit: I'm tired, and I'm making a bunch of stupid mistakes. Figure 6 and figure 5 are directly at odds with each other. I can't account for the discrepancy, so I'm going to reduce the signal to noise ratio, and get rid of some of my other comments. I apologize to everyone for spamming stupidly.
[edit: I'm guessing you are referring to chart 6, but that data is restricted to "days when they did at least some work".]