Logical indicator to include percent symbol in output.
Default is FALSE.
digits
number of digits to round large percentages (i.e. greater than 10%).
Smaller percentages are rounded to digits + 1 places.
Default is 0
big.mark
Character used between every 3 digits to separate
hundreds/thousands/millions/etc.
Default is ",", except when decimal.mark = "," when the default is a space.
decimal.mark
The character to be used to indicate the numeric decimal point.
Default is "." or getOption("OutDec")