Problem with setGlobalExcludedIps

I’m trying to excluded some IPs from the report, using SitesManager.setGlobalExcludedIps, but there is no affect at all. I use
CustomVariables.getCustomVariables and
CustomVariables.getCustomVariablesValuesFromNameId for the reports. Does setGlobalExcludedIps affects on these params or no?

Only affects new visits

oh…so, it doesn’t affect of the existing records? If so, is any way to exclude the IPs from old report?