The statistic "x number extracted from Excel" is not overly useful.

It does not give the user specific information wrt added users, changed users etc
Solution
It would be more informative if we showed
"x participants was created. y participants was updated"
If no participants were created or changed by the import, show
"No changes were made"
If some were created, but none modified:
"10 participants was created."
If some were changed, but none created:
"8 participants was updated."
If both new and changed:
"8 participants was created. 2 participants was updated."