Frequencies for first 10,000 rows of vin_bt variable in vehicle dataset : vin_bt | Freq. Percent Cum. ------------+----------------------------------- | 51 0.51 0.51 2D | 247 2.47 2.98 2H | 487 4.87 7.85 2L | 34 0.34 8.19 2P | 16 0.16 8.35 2T | 67 0.67 9.02 2W | 81 0.81 9.83 3C | 32 0.32 10.15 3D | 8 0.08 10.23 4C | 11 0.11 10.34 4D | 2,471 24.71 35.05 4H | 120 1.20 36.25 4L | 6 0.06 36.31 4P | 30 0.30 36.61 4T | 3 0.03 36.64 4W | 418 4.18 40.82 99 | 708 7.08 47.90 AT | 9 0.09 47.99 BU | 19 0.19 48.18 CB | 76 0.76 48.94 CC | 93 0.93 49.87 CG | 51 0.51 50.38 CH | 2 0.02 50.40 CM | 1 0.01 50.41 CP | 850 8.50 58.91 CV | 86 0.86 59.77 CW | 24 0.24 60.01 CY | 2 0.02 60.03 DP | 4 0.04 60.07 DS | 376 3.76 63.83 EC | 17 0.17 64.00 EN | 1 0.01 64.01 ES | 75 0.75 64.76 EV | 3 0.03 64.79 EW | 1 0.01 64.80 FB | 5 0.05 64.85 FC | 6 0.06 64.91 GL | 7 0.07 64.98 HB | 1 0.01 64.99 HR | 1 0.01 65.00 HT | 2 0.02 65.02 IC | 77 0.77 65.79 IE | 10 0.10 65.89 LB | 5 0.05 65.94 LL | 6 0.06 66.00 MH | 8 0.08 66.08 MP | 37 0.37 66.45 MR | 2 0.02 66.47 MS | 6 0.06 66.53 MX | 8 0.08 66.61 MY | 15 0.15 66.76 NB | 1 0.01 66.77 PC | 326 3.26 70.03 PK | 1,389 13.89 83.92 PS | 125 1.25 85.17 RD | 4 0.04 85.21 RS | 389 3.89 89.10 RT | 1 0.01 89.11 S1 | 1 0.01 89.12 S2 | 117 1.17 90.29 SD | 5 0.05 90.34 SN | 4 0.04 90.38 SV | 270 2.70 93.08 SW | 217 2.17 95.25 T | 3 0.03 95.28 TB | 39 0.39 95.67 TL | 42 0.42 96.09 TM | 105 1.05 97.14 UT | 188 1.88 99.02 VC | 1 0.01 99.03 VN | 88 0.88 99.91 VW | 1 0.01 99.92 XT | 1 0.01 99.93 YY | 7 0.07 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 18 Apr 2016