Date: type `Date`.
TickerLast: type `chr`. The ticker as of December 2015
Ticker: type `chr`. Monthly ticker
period
Company: type `chr`. The name of company with TickerLast
CapGroupLast: type `chr`. Company market capitalization group
as of December 2015, one of: MicroCap, SmallCap, MidCap or LargeCap
CapGroup: type `chr`. Monthly market capitalization group
GICS: type `chr`. 6 digit S&P GICS code
Sector: type `chr`. One of 10 sectors specified by the first
two digits of the GICS code
Return: type `num`. Arithmetic stock return from one period
to the next in decimal form
RetExDiv: type `num`.
Price: type `num`. Stock price at each time period in decimal
form
PrcSplitAdj: type `num`.
Ret4WkBill: type `num`. Return of 4 week Treasury bill
Ret13WkBill: type `num`. Return of 13 week Treasury bill
Ret1YrBill: type `num`. Return of 1 year Treasury bill
mktIndexCRSP: type `num`. CRSP value weighted market return