Frequencies for first 10,000 rows of vin_bt variable in vehicle dataset : vin_bt | Freq. Percent Cum. ------------+----------------------------------- | 36 0.36 0.36 2D | 166 1.66 2.02 2H | 402 4.02 6.04 2L | 43 0.43 6.47 2P | 28 0.28 6.75 2T | 27 0.27 7.02 2W | 33 0.33 7.35 3C | 81 0.81 8.16 3D | 10 0.10 8.26 4C | 214 2.14 10.40 4D | 2,712 27.12 37.52 4H | 52 0.52 38.04 4L | 3 0.03 38.07 4P | 37 0.37 38.44 4T | 1 0.01 38.45 4W | 217 2.17 40.62 99 | 571 5.71 46.33 AC | 1 0.01 46.34 AT | 18 0.18 46.52 BU | 12 0.12 46.64 CB | 49 0.49 47.13 CC | 77 0.77 47.90 CG | 38 0.38 48.28 CL | 1 0.01 48.29 CP | 712 7.12 55.41 CV | 125 1.25 56.66 CW | 111 1.11 57.77 DP | 3 0.03 57.80 DS | 402 4.02 61.82 EC | 23 0.23 62.05 EN | 3 0.03 62.08 ES | 16 0.16 62.24 EV | 4 0.04 62.28 EW | 2 0.02 62.30 FB | 5 0.05 62.35 FC | 3 0.03 62.38 GL | 3 0.03 62.41 HR | 2 0.02 62.43 IC | 62 0.62 63.05 IE | 9 0.09 63.14 LL | 3 0.03 63.17 MH | 9 0.09 63.26 MM | 1 0.01 63.27 MP | 1 0.01 63.28 MS | 4 0.04 63.32 MX | 9 0.09 63.41 MY | 12 0.12 63.53 PC | 363 3.63 67.16 PK | 943 9.43 76.59 PS | 138 1.38 77.97 RD | 8 0.08 78.05 RS | 488 4.88 82.93 RT | 9 0.09 83.02 S2 | 3 0.03 83.05 SD | 3 0.03 83.08 SN | 4 0.04 83.12 SV | 411 4.11 87.23 SW | 232 2.32 89.55 T | 2 0.02 89.57 TB | 15 0.15 89.72 TL | 26 0.26 89.98 TM | 83 0.83 90.81 UT | 863 8.63 99.44 VN | 38 0.38 99.82 YY | 18 0.18 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 18 Apr 2016