Why might the Fugitive Slave Act have allowed for higher fees to be paid to commissioners who returned suspected runaway slaves to slaveholders?

People had suspicion that people wanted slaves returned. But with a slave act, it was now known that people are serious about it. Because the seriousness about the Slave return was high, people began to ask for large rewards to return slaves.

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the graphs indicate that few people in bolivia work in industry, as that is the least expressive sector shown in the respective graphic.