That sounds like extrapolation when linking a general survey on vacation habits to specific percentages on verification of identity documents.
My intuition tells me that a good vacation planner can very well forget their papers until the last minute; the direct link seems a bit weak.
There is a tangible proof missing in the survey itself, such as direct questions about managing travel documents.
Without that, it's like assuming that because someone buys their house early, they will automatically have their technical diagnostics up to date; it doesn't follow.
For credibility, the survey should have specifically probed the behavior related to identity papers.