Frequencies for first 10,000 rows of vin_bt variable in vehicle dataset : vin_bt | Freq. Percent Cum. ------------+----------------------------------- | 6 0.06 0.06 2D | 95 0.95 1.01 2H | 228 2.28 3.29 2L | 17 0.17 3.46 2P | 20 0.20 3.66 2T | 11 0.11 3.77 2W | 41 0.41 4.18 3C | 61 0.61 4.79 3D | 2 0.02 4.81 3P | 20 0.20 5.01 4B | 2 0.02 5.03 4C | 327 3.27 8.30 4D | 2,729 27.29 35.59 4H | 62 0.62 36.21 4P | 23 0.23 36.44 4T | 1 0.01 36.45 4W | 264 2.64 39.09 5D | 5 0.05 39.14 99 | 497 4.97 44.11 AC | 1 0.01 44.12 AT | 45 0.45 44.57 BU | 13 0.13 44.70 C4 | 6 0.06 44.76 CB | 54 0.54 45.30 CC | 68 0.68 45.98 CG | 40 0.40 46.38 CH | 5 0.05 46.43 CP | 534 5.34 51.77 CS | 1 0.01 51.78 CV | 105 1.05 52.83 CW | 332 3.32 56.15 DS | 525 5.25 61.40 EC | 16 0.16 61.56 EN | 4 0.04 61.60 ES | 91 0.91 62.51 FC | 7 0.07 62.58 GG | 4 0.04 62.62 GL | 2 0.02 62.64 IC | 37 0.37 63.01 IE | 5 0.05 63.06 LB | 16 0.16 63.22 LL | 1 0.01 63.23 LM | 1 0.01 63.24 MH | 5 0.05 63.29 MP | 3 0.03 63.32 MS | 7 0.07 63.39 MX | 13 0.13 63.52 MY | 13 0.13 63.65 PC | 308 3.08 66.73 PK | 615 6.15 72.88 PS | 97 0.97 73.85 RD | 10 0.10 73.95 RS | 825 8.25 82.20 RT | 12 0.12 82.32 S1 | 2 0.02 82.34 S2 | 13 0.13 82.47 SN | 2 0.02 82.49 SV | 313 3.13 85.62 SW | 89 0.89 86.51 T | 5 0.05 86.56 TB | 32 0.32 86.88 TL | 19 0.19 87.07 TM | 70 0.70 87.77 UT | 1,201 12.01 99.78 VN | 11 0.11 99.89 VW | 1 0.01 99.90 YY | 10 0.10 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 18 Apr 2016