Frequencies for first 10,000 rows of smsarfip variable in natl1999 dataset :

       FIPS |
PMSA/MSA of |
  Residence |      Freq.     Percent        Cum.
------------+-----------------------------------
       0000 |      3,099       30.99       30.99
       0450 |        263        2.63       33.62
       0520 |          1        0.01       33.63
       0920 |         18        0.18       33.81
       1000 |      2,078       20.78       54.59
       1145 |          1        0.01       54.60
       1560 |          2        0.02       54.62
       1800 |         84        0.84       55.46
       1840 |          1        0.01       55.47
       2030 |        351        3.51       58.98
       2180 |        263        2.63       61.61
       2650 |        264        2.64       64.25
       2750 |          1        0.01       64.26
       3440 |        824        8.24       72.50
       4320 |          1        0.01       72.51
       4680 |          1        0.01       72.52
       4800 |          1        0.01       72.53
       5160 |      1,270       12.70       85.23
       5200 |          1        0.01       85.24
       5240 |        866        8.66       93.90
       5560 |          1        0.01       93.91
       6015 |          1        0.01       93.92
       6080 |          1        0.01       93.93
       8600 |        402        4.02       97.95
       9999 |        205        2.05      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Dec 2015