Exclude Top 1% records from webi report

Hello Friends,

Please help me on this requirement. I am having tough time to resolve.

I have a requirement where I need to Exclude Top 1% records from webi report.

First lets try on Top 1 row: We need to exclude this top 1 record and do average of days from 2nd value to till last value) on rest of the records. let me know how to achieve this with ranking or any other function. Greatly appreciated for your help.

Cal-MonthDocumentDays01/20181821001/20181822001/20181823001/20181824201/20181834301/20181835001/20181865501/20182576501/201825777

Result after sorting and removing last record - 7 days is the top record. so average of days on rest of records is 2.1Average2.1