Q: # unique companies in entire db
A: 84,472 unique companies (totally there are 563,295 company records)

Q: # unique companies per year
A:

year

 company_count

1989

         16985

1990

         20936

1991

         23554

1992

         24331

1993

         26938

1994

         31144

1995

         34477

1996

         35992

1997

         38228

1998

         41692

1999

         43663

2000

         51321

2001

         60294

2002

         56944

2003

         56796



Q: # unique Primary NAICS
A:
498

Q: # unique Primary NAICS per year

A:

year

 uniq_naics_count

1989

              143

1990

              145

1991

              144

1992

              148

1993

              148

1994

              147

1995

              147

1996

              148

1997

              148

1998

              148

1999

              149

2000

              149

2001

              457

2002

              466

2003

              480



Q: # companies that have more than one unique Primary NAICS (over time)
A: 22,288
Here is the distribution regarding "how many companies have how many
different NAICS over the years":
 

diff_naics_count

 company_count

               7

             1

               6

            10

               5

           101

               4

           673

               3

          3827

               2

         17676



Q: # unique zip codes in zipdata
or # unique places in zip data set

A: 42,193

 

Q: How many companies change their zip code and how often - distribution?
A:
"how often" = diff_zip_count -1
"how many" = company_count

 

diff_zip_count

company_count

7

 4

6

 25

5

 165

4

 793

3

 4220

2

 19759

 

Q: the sales in million per employee = $sales / # employees

A:

 

year

 sum_sales

 sum_employ

 sales per employee

1989

2074780

 14275279

0.15

1990

2694950

 17606668

0.15

1991

2875140

 18071001

0.16

1992

2952690

 17938409

0.16

1993

3053900

 17989674

0.17

1994

3426370

 18792961

0.18

1995

3789250

 20320100

0.19

1996

4185210

 21171157

0.2

1997

4516210

 22736662

0.2

1998

5167000

 24915589

0.21

1999

5482400

 25897635

0.21

2000

6343680

 28776028

0.22

2001

8376420

 39317977

0.21

2002

8703030

 40396389

0.22

2003

9015400

 41274313

0.22