Dear all,

I have the following dataset

Code:
* Example generated by -dataex-. To install: ssc install dataex
clear
input str4 loc str12 isin str6 datacqtr
"DEU" ""             "2005Q1"
"ITA" ""             "2005Q2"
"DNK" ""             "2005Q3"
"ITA" ""             "2005Q4"
"GBR" ""             "2006Q1"
"SWE" ""             "2006Q2"
"GBR" ""             "2006Q3"
"DEU" ""             "2006Q4"
"NLD" ""             "2007Q1"
"ITA" ""             "2007Q2"
"DEU" ""             "2007Q3"
"GRC" ""             "2007Q4"
"SWE" ""             "2008Q1"
"SWE" ""             "2008Q2"
"DEU" ""             "2008Q3"
"ITA" ""             "2008Q4"
"SWE" ""             "2009Q1"
"GBR" ""             "2009Q2"
"DEU" ""             "2009Q3"
"POL" ""             "2009Q4"
"SWE" ""             "2010Q1"
"ITA" ""             "2010Q2"
"NLD" ""             "2010Q3"
"DEU" ""             "2010Q4"
"DEU" ""             "2011Q1"
"GBR" ""             "2011Q2"
"DEU" ""             "2011Q3"
"GRC" ""             "2011Q4"
"POL" ""             "2012Q1"
"NLD" ""             "2012Q2"
"DEU" ""             "2012Q3"
"SWE" ""             "2012Q4"
"DEU" ""             "2013Q1"
"NLD" ""             "2013Q2"
"DNK" ""             "2013Q3"
"SWE" ""             "2013Q4"
"SWE" ""             "2014Q1"
"NLD" ""             "2014Q2"
"NLD" ""             "2014Q3"
"NLD" ""             "2014Q4"
"SWE" ""             "2015Q1"
"GRC" ""             "2015Q2"
"GBR" ""             "2015Q3"
"DNK" ""             "2015Q4"
"NLD" "ANN4327C1220" "2005Q1"
"NLD" "ANN4327C1220" "2005Q2"
"NLD" "ANN4327C1220" "2005Q3"
"NLD" "ANN4327C1220" "2005Q4"
"NLD" "ANN4327C1220" "2006Q1"
"NLD" "ANN4327C1220" "2006Q2"
"NLD" "ANN4327C1220" "2006Q3"
"NLD" "ANN4327C1220" "2006Q4"
"NLD" "ANN4327C1220" "2007Q1"
"NLD" "ANN4327C1220" "2007Q2"
"NLD" "ANN4327C1220" "2007Q3"
"NLD" "ANN4327C1220" "2007Q4"
"NLD" "ANN4327C1220" "2008Q1"
"NLD" "ANN4327C1220" "2008Q2"
"NLD" "ANN4327C1220" "2008Q3"
"NLD" "ANN4327C1220" "2008Q4"
"NLD" "ANN4327C1220" "2009Q1"
"NLD" "ANN4327C1220" "2009Q2"
"NLD" "ANN4327C1220" "2009Q3"
"NLD" "ANN4327C1220" "2009Q4"
"NLD" "ANN4327C1220" "2010Q1"
"NLD" "ANN4327C1220" "2010Q2"
"NLD" "ANN4327C1220" "2010Q3"
"NLD" "ANN4327C1220" "2010Q4"
"NLD" "ANN4327C1220" "2011Q1"
"NLD" "ANN4327C1220" "2011Q2"
"NLD" "ANN4327C1220" "2011Q3"
"NLD" "ANN4327C1220" "2011Q4"
"NLD" "ANN4327C1220" "2012Q1"
"NLD" "ANN4327C1220" "2012Q2"
"NLD" "ANN4327C1220" "2012Q3"
"NLD" "ANN4327C1220" "2012Q4"
"NLD" "ANN4327C1220" "2013Q1"
"NLD" "ANN4327C1220" "2013Q2"
"NLD" "ANN4327C1220" "2013Q3"
"NLD" "ANN4327C1220" "2013Q4"
"NLD" "ANN4327C1220" "2014Q1"
"NLD" "ANN4327C1220" "2014Q2"
"NLD" "ANN4327C1220" "2014Q3"
"NLD" "ANN4327C1220" "2014Q4"
"NLD" "ANN4327C1220" "2015Q1"
"NLD" "ANN4327C1220" "2015Q2"
"NLD" "ANN4327C1220" "2015Q3"
"NLD" "ANN4327C1220" "2015Q4"
"AUT" "AT000000STR1" "2005Q4"
"AUT" "AT000000STR1" "2006Q1"
"AUT" "AT000000STR1" "2006Q2"
"AUT" "AT000000STR1" "2006Q3"
"AUT" "AT000000STR1" "2006Q4"
"AUT" "AT000000STR1" "2007Q1"
"AUT" "AT000000STR1" "2007Q2"
"AUT" "AT000000STR1" "2007Q3"
"AUT" "AT000000STR1" "2007Q4"
"AUT" "AT000000STR1" "2008Q1"
"AUT" "AT000000STR1" "2008Q2"
"AUT" "AT000000STR1" "2008Q3"
end
and I'm trying to explore the data, with the objective to have a table like the following:

Array

Where country is the variable "loc", firms are identifies by "ISIN" over quarters ("datacqtr")


I tried with collapse function

Code:
collapse (unique) firms= isin (count) observations = isin , by(loc)
Nevertheless I realize tha collapse doesn't have stats related to unique/distinct id identifiers.

More than happy to receive your help!