=== Data Summary (208 rows) ===
 0: Summary of data from national surveys, censuses and regulators |  |  |  |  |  |  |  |  |  |  | 
 1: [values in square brackets not used] |  |  | Drinking water |  |  |  |  |  |  |  | 
 2:  |  |  | Total |  |  |  |  |  |  | Urban | 
 3: Source | Type | Year | Improved | Piped | Surface water | No more than 30 mins | Accessible on premises | Available when needed | Free from contamination | Improved | Piped
 4: source | type | year | w_imp_t | w_pip_t | w_ns_t | w_30min_t | w_premises_t | w_available_t | w_quality_t | w_imp_u | w_pip_u
 5: NGA_1990_DHS | Survey with microdata | 1990 | [47] | [25] | [40] | #N/A | #N/A | #N/A | #N/A | [87] | [63]
 6: NGA_1995_MICS | Survey | 1995 | [53] | [20] | [29] | #N/A | #N/A | #N/A | #N/A | #N/A | #N/A
 7: NGA_1996_CEN | Census | 1996 | #N/A | #N/A | #N/A | #N/A | #N/A | #N/A | #N/A | [82] | [68]
 8: NGA_1999_MICS | Survey | 1999 | [63] | [17] | [25] | #N/A | #N/A | #N/A | #N/A | [89] | [42]
 9: NGA_1999_DHS | Survey with microdata | 1999 | [38] | [24] | [25] | #N/A | #N/A | #N/A | #N/A | [84] | [50]
10: NGA_2000_AFB | Survey with microdata | 2000 | #N/A | #N/A | #N/A | #N/A | #N/A | [75] | #N/A | #N/A | #N/A
11: NGA_2000_CLS | Survey | 2000 | [55] | [21] | [0] | #N/A | #N/A | #N/A | #N/A | 86.9 | 45.3
12: NGA_2002_CWIQ | Survey with microdata | 2002 | #N/A | #N/A | #N/A | [78] | #N/A | #N/A | #N/A | #N/A | #N/A
13: NGA_2003_AFB | Survey with microdata | 2003 | #N/A | #N/A | #N/A | #N/A | #N/A | [51] | #N/A | #N/A | #N/A
14: NGA_2003_DHS | Survey with microdata | 2003 | #N/A | #N/A | #N/A | [85] | [23] | #N/A | #N/A | 74.50767662931673 | 32.4
15: NGA_2004_LSS | Survey with microdata | 2004 | [66] | [24] | [16] | [89] | [47] | #N/A | #N/A | 90.76567962264151 | 43.33692
16: NGA_2005_AFB | Survey with microdata | 2005 | #N/A | #N/A | #N/A | #N/A | #N/A | [61] | #N/A | #N/A | #N/A
17: NGA_2005_RADWQ | Survey | 2005 | #N/A | #N/A | #N/A | #N/A | #N/A | #N/A | [77] | #N/A | #N/A
18: NGA_2006_CWIQ | Survey | 2006 | [61] | [14] | [20] | #N/A | #N/A | #N/A | #N/A | 87.3 | 28.9
19: NGA_2006_GHS | Survey | 2006 | [55] | [11] | [28] | #N/A | #N/A | #N/A | #N/A | 83 | 25.299999999999997
20: NGA_2007_MICS | Survey with microdata | 2007 | #N/A | #N/A | #N/A | [86] | [26] | #N/A | #N/A | 83.42800415819914 | 29.023517598169967
21: NGA_2008_AFB | Survey with microdata | 2008 | #N/A | #N/A | #N/A | #N/A | #N/A | [61] | #N/A | #N/A | #N/A
22: NGA_2008_BLS | Survey | 2008 | [62] | [8] | [19] | #N/A | #N/A | #N/A | #N/A | 88.39999999999998 | 18.4
23: NGA_2008_DHS | Survey with microdata | 2008 | [58] | [10] | [18] | [91] | [32] | #N/A | #N/A | 83.7 | 21.158304570000002
24: NGA_2009_MHS | Survey with microdata | 2009 | [80] | [40] | [9] | #N/A | #N/A | #N/A | #N/A | [86] | [46]
25: NGA_2009_LSS | Survey with microdata | 2009 | [66] | [13] | [19] | #N/A | #N/A | #N/A | #N/A | 89.02700000000002 | 22.096128399900003
26: NGA_2010_MIS | Survey with microdata | 2010 | [60] | [11] | [16] | #N/A | #N/A | #N/A | #N/A | 83.62132652390574 | 22.459453007976848
27: NGA_2010_CEN | Census | 2010 | [67] | [12] | [14] | #N/A | #N/A | #N/A | #N/A | 85.53560931537577 | 23.32848989082363
28: NGA_2011_IBNET | Other | 2011 | #N/A | #N/A | #N/A | #N/A | #N/A | #N/A | #N/A | #N/A | #N/A
29: NGA_2011_LSMS | Survey with microdata | 2011 | [72] | [11] | [12] | [79] | [19] | #N/A | #N/A | 79.59235789316244 | 15.81539976715814
30: NGA_2011_MICS | Survey with microdata | 2011 | [68] | [14] | [13] | [87] | [30] | #N/A | #N/A | 93.39999999999999 | 25.540255379999998
31: NGA_2012_GATS | Survey | 2012 | #N/A | #N/A | #N/A | #N/A | #N/A | #N/A | #N/A | #N/A | #N/A
32: NGA_2012_IBNET | Other | 2012 | #N/A | #N/A | #N/A | #N/A | #N/A | #N/A | #N/A | #N/A | #N/A
33: NGA_2013_AFB | Survey with microdata | 2013 | #N/A | #N/A | #N/A | #N/A | #N/A | [60] | #N/A | #N/A | #N/A
34: NGA_2013_IBNET | Other | 2013 | #N/A | #N/A | #N/A | #N/A | #N/A | #N/A | #N/A | #N/A | #N/A
35: NGA_2013_GHS | Survey with microdata | 2013 | [79] | [13] | [10] | [93] | [11] | #N/A | #N/A | 95.55999999999999 | 21.17730098
36: NGA_2013_DHS | Survey with microdata | 2013 | [65] | [10] | [14] | [88] | [22] | #N/A | #N/A | 89.91312249471387 | 17.91258768331042
37: NGA_2014_IBNET | Other | 2014 | #N/A | #N/A | #N/A | #N/A | #N/A | #N/A | #N/A | #N/A | #N/A
38: NGA_2014_NNHS | Survey with microdata | 2014 | [59] | [11] | [11] | #N/A | #N/A | #N/A | #N/A | #N/A | #N/A
39: NGA_2015_AFB | Survey with microdata | 2015 | #N/A | #N/A | #N/A | #N/A | #N/A | [72] | #N/A | #N/A | #N/A
40: NGA_2015_MIS | Survey with microdata | 2015 | [71] | [13] | [10] | [96] | [43] | #N/A | #N/A | 92.58592999999999 | 19.846930484999998
41: NGA_2016_GHS | Survey with microdata | 2016 | [79] | [13] | [9] | [79] | [24] | #N/A | #N/A | 95.64226 | 19.09232124125
42: NGA_2016_PMA | Survey with microdata | 2016 | [83] | [17] | [6] | [90] | [13] | [82] | #N/A | 96.68996000000001 | 24.2143596225
43: NGA_2017_AFB | Survey with microdata | 2017 | #N/A | #N/A | #N/A | #N/A | #N/A | [76] | #N/A | #N/A | #N/A
44: NGA_2017_PMA | Survey with microdata | 2017 | [82] | [18] | [7] | [92] | [13] | [84] | #N/A | 96.23128 | 25.5556773225
45: NGA_2017_MICS | Survey with microdata | 2017 | [69] | [12] | [10] | [93] | [33] | [85] | [30] | 91.44079 | 19.391665720000002
46: NGA_2018_MTF | Survey with microdata | 2018 | [47] | [27] | [1] | #N/A | #N/A | #N/A | #N/A | 98.38545344783398 | [80]
47: NGA_2018_LSS | Survey | 2018 | [74] | [9] | [8] | [96] | [42] | #N/A | #N/A | 94.73726500000001 | 14.08893
48: NGA_2018_PMA | Survey with microdata | 2018 | [81] | [19] | [8] | [94] | [10] | [86] | #N/A | 96.86327 | 28.398170022044003
49: NGA_2018_NNHS | Survey with microdata | 2018 | [57] | #N/A | #N/A | #N/A | #N/A | #N/A | #N/A | #N/A | #N/A