I have a dataset D2 containing total volume of issuances of a financial product by company by month.
Company month Volume
AWK 2013-01 24244000
AWK 2013-02 12294000
AWK 2013-03 17254000
AWK 2013-04 13939000
AWK 2013-05 38757000
AWK 2013-06 34600000
AWK 2013-08 25240000
I would like to filter out companies that have traded less than 8 months per year in average.
When a company has not traded on a specific month, D2 does not contain any information and D2$month goes directly to the next month.