Modifying Purpose Statement when reapplying

[Abdelazar]

How important is it to modify one's statement of purpose when reapplying to programs?

In my case, I was close to being accepted at each of the programs to which I am reapplying (first on waitlist; POI wanted to accept me but there turned out to be no funding this year; invited to interview on campus). My main research interests have not changed and the new academic work I have done since applying last season (paper presented, language class) is probably better presented on my CV or elsewhere on the application rather than mentioning it in the SOP. I will likely change up the wording in some parts, but my main question is how substantial should these changes to be? Should I write a new "hook"? I'm guessing that the admissions committee will not hold up my previous SOP to my current one and do a close textual analysis for changes, but I am concerned about seeming lazy if my SOP is largely unchanged.