Frequencies for first 10,000 rows of vin_bt variable in vehicle dataset : vin_bt | Freq. Percent Cum. ------------+----------------------------------- | 30 0.30 0.30 2D | 135 1.35 1.65 2H | 301 3.01 4.66 2L | 27 0.27 4.93 2P | 25 0.25 5.18 2T | 16 0.16 5.34 2W | 49 0.49 5.83 3C | 93 0.93 6.76 3D | 1 0.01 6.77 3P | 11 0.11 6.88 4B | 1 0.01 6.89 4C | 279 2.79 9.68 4D | 2,706 27.06 36.74 4H | 42 0.42 37.16 4L | 1 0.01 37.17 4P | 25 0.25 37.42 4T | 1 0.01 37.43 4W | 236 2.36 39.79 5D | 2 0.02 39.81 99 | 569 5.69 45.50 AT | 21 0.21 45.71 BU | 19 0.19 45.90 C4 | 2 0.02 45.92 CB | 57 0.57 46.49 CC | 78 0.78 47.27 CG | 35 0.35 47.62 CH | 3 0.03 47.65 CP | 643 6.43 54.08 CV | 95 0.95 55.03 CW | 223 2.23 57.26 DP | 3 0.03 57.29 DS | 456 4.56 61.85 EC | 15 0.15 62.00 EN | 2 0.02 62.02 ES | 10 0.10 62.12 EW | 1 0.01 62.13 FB | 1 0.01 62.14 FC | 2 0.02 62.16 GL | 1 0.01 62.17 IC | 55 0.55 62.72 IE | 10 0.10 62.82 LB | 4 0.04 62.86 LL | 3 0.03 62.89 MH | 4 0.04 62.93 MK | 1 0.01 62.94 MM | 1 0.01 62.95 MP | 1 0.01 62.96 MS | 4 0.04 63.00 MX | 16 0.16 63.16 MY | 10 0.10 63.26 NB | 2 0.02 63.28 PC | 312 3.12 66.40 PK | 803 8.03 74.43 PS | 110 1.10 75.53 RD | 7 0.07 75.60 RS | 602 6.02 81.62 RT | 7 0.07 81.69 S2 | 7 0.07 81.76 SD | 2 0.02 81.78 SN | 2 0.02 81.80 SV | 431 4.31 86.11 SW | 217 2.17 88.28 T | 7 0.07 88.35 TB | 24 0.24 88.59 TL | 21 0.21 88.80 TM | 89 0.89 89.69 UT | 990 9.90 99.59 VN | 28 0.28 99.87 YY | 13 0.13 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 18 Apr 2016