OSM SQLite Experiment: Frequency of key surface (elem type k)

1	asphalt	118950	31101389	27847
2	unpaved	102038	12242157	999
3	paved	16115	4269034	5290
4	concrete	24715	4110010	6244
5	paving_stones	27692	3984237	12007
6	ground	5691	3448674	895
7	gravel	6522	2223603	2952
8	dirt	2487	1720971	697
9	grass	9690	1288827	10795
10	compacted	1620	1225275	917
11	sand	4548	566226	9655
12	sett	3136	508512	2005
13	fine_gravel	2320	465914	734
14	wood	3863	238627	498
15	concrete:plates	1306	202049	326
16	earth	111	152223	61
17	cobblestone	1054	145104	518
18	pebblestone	417	138866	766
19	grass_paver	544	48576	614
20	metal	1315	47384	69
21	artificial_turf	623	44177	300
22	tartan	463	37533	4304
23	unhewn_cobblestone	66	41555	96
24	clay	202	36787	578
25	mud	179	29765	492
26	concrete:lanes	40	29840	12
27	rock	169	26592	127
28	stone	297	13160	72
29	woodchips	481	12600	73
30	dirt/sand	76	8440	21
31	bricks	64	7786	28
32	soil	6	7148	1
33	brick	87	6983	55
34	acrylic	36	5635	38
35	chipseal	4	5674	2
36	trail		5503
37	cobblestone:flattened	5	5148	21
38	rubber	1118	3468	102
39	plastic	3371	1145	7
40	metal_grid	250	3535	1
41	cement	14	2631	23
42	stepping_stones	40	2584	4
43	ice	22	2449	24
44	hard	3	2303	7
45	tiles	16	1629	27
46	rocky	13	1341	58
47	paving_stones:30	8	1349	6
48	interlock		1310
49	shells	11	1168	4
50	bitmac	1	1098