It sounds like by "it" you mean the percentage of homeless with a significant mental illness..."that they cannot provide for themselves" (whatever the sentence was meant to mean). But the only 26% on that page is this:
"Over one-quarter (26%) of respondents identified job loss as the primary cause of their homelessness. "
"Over one-quarter (26%) of respondents identified job loss as the primary cause of their homelessness. "