Historical PEs ratio of ETF/industries?

Is there anyway to get historical PE's ratio for ETF's? Like 3 to 10 year historical average PE ratio?

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Like let's say I am using these ETF's:

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XLI Industrial Sector Current PE: 22.38

XLB Materials Sector Current PE: 21.95

XLK Tech Sector Current PE: 29.37

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It's very easy to fine current PE's of these ETF's but I can't seem to find the historical average range.