E.g., in one case, I see x months on https://my.uscis.gov/account/applicant and x+4 months on https://egov.uscis.gov/processing-times/, for the same USCIS field office, even though the naturalization candidate applied 1 month ago (so I'd expect to see x months on https://my.uscis.gov/account/applicant and x+1 months on https://egov.uscis.gov/processing-times).
*These completion projections are based on case processing for applicants who have been lawful permanent residents for at least 5 years. For all other applicants, completion projections may vary.
The number displayed on https://egov.uscis.gov/processing-times/ reflects the time it took the USCIS to complete 80% of cases over the past 6 months.
We generally process cases in the order we receive them. This processing time is based on how long it took us to complete 80% of adjudicated cases over the past six months. Each case is unique, and some cases may take longer than others. Processing times should be used as a reference point, not an absolute measure of how long your case will take to be completed.
Does https://my.uscis.gov/account/applicant use a different percentage?
Screenshot from https://my.uscis.gov/account/applicant: