Database schema:

CREATE TABLE "Country" (
	"CountryCode" TEXT NOT NULL -- example: ['ABW', 'ADO'],
	"ShortName" TEXT -- example: ['Albania', 'Afghanistan'],
	"TableName" TEXT -- example: ['Albania', 'Afghanistan'],
	"LongName" TEXT -- example: ['Islamic State of Afghanistan', 'Republic of Albania'],
	"Alpha2Code" TEXT -- example: ['AL', 'AF'],
	"CurrencyUnit" TEXT -- example: ['Albanian lek', 'Afghan afghani'],
	"SpecialNotes" TEXT -- example: ['', 'Fiscal year end: March 20; reporting period for na'],
	"Region" TEXT -- example: ['Europe & Central Asia', 'South Asia'],
	"IncomeGroup" TEXT -- example: ['Low income', 'Upper middle income'],
	"Wb2Code" TEXT -- example: ['AL', 'AF'],
	"NationalAccountsBaseYear" TEXT -- example: ['2002/03', 'Original chained constant price data are rescaled.'],
	"NationalAccountsReferenceYear" TEXT -- example: ['', '1996'],
	"SnaPriceValuation" TEXT -- example: ['', 'Value added at basic prices (VAB)'],
	"LendingCategory" TEXT -- example: ['IBRD', 'IDA'],
	"OtherGroups" TEXT -- example: ['', 'HIPC'],
	"SystemOfNationalAccounts" TEXT -- example: ['Country uses the 1993 System of National Accounts ', 'Country uses the 1968 System of National Accounts '],
	"AlternativeConversionFactor" TEXT, 
	"PppSurveyYear" TEXT -- example: ['', 'Rolling'],
	"BalanceOfPaymentsManualInUse" TEXT -- example: ['', 'IMF Balance of Payments Manual, 6th edition.'],
	"ExternalDebtReportingStatus" TEXT -- example: ['Actual', ''],
	"SystemOfTrade" TEXT -- example: ['Special trade system', 'General trade system'],
	"GovernmentAccountingConcept" TEXT -- example: ['Consolidated central government', 'Budgetary central government'],
	"ImfDataDisseminationStandard" TEXT -- example: ['', 'General Data Dissemination System (GDDS)'],
	"LatestPopulationCensus" TEXT -- example: ['1979', '2011'],
	"LatestHouseholdSurvey" TEXT -- example: ['Multiple Indicator Cluster Survey (MICS), 2010/11', 'Demographic and Health Survey (DHS), 2008/09'],
	"SourceOfMostRecentIncomeAndExpenditureData" TEXT -- example: ['Living Standards Measurement Study Survey (LSMS), ', 'Integrated household survey (IHS), 2008'],
	"VitalRegistrationComplete" TEXT -- example: ['', 'Yes'],
	"LatestAgriculturalCensus" TEXT -- example: ['2012', '2013/14'],
	"LatestIndustrialData" INTEGER -- example: ['2010', '2011'],
	"LatestTradeData" INTEGER -- example: ['2013', '2006'],
	"LatestWaterWithdrawalData" INTEGER -- example: ['2000', '2006'],
	PRIMARY KEY ("CountryCode")
)


CREATE TABLE "CountryNotes" (
	"Countrycode" TEXT NOT NULL -- example: ['ABW', 'ADO'],
	"Seriescode" TEXT NOT NULL -- example: ['EG.ELC.RNEW.ZS', 'EG.EGY.PRIM.PP.KD'],
	"Description" TEXT -- example: ['Sources: Estimated based on UN Energy Statistics (', 'Sources: UN Energy Statistics (2014)'],
	PRIMARY KEY ("Countrycode", "Seriescode"), 
	CONSTRAINT fk_countrynotes_series FOREIGN KEY("Seriescode") REFERENCES "Series" ("SeriesCode"),
	CONSTRAINT fk_countrynotes_country FOREIGN KEY("Countrycode") REFERENCES "Country" ("CountryCode")
)


CREATE TABLE "Footnotes" (
	"Countrycode" TEXT NOT NULL -- example: ['ABW', 'ADO'],
	"Seriescode" TEXT NOT NULL -- example: ['BX.KLT.DINV.CD.WD', 'AG.LND.FRST.K2'],
	"Year" TEXT -- example: ['YR1990', 'YR2000'],
	"Description" TEXT -- example: ['Not specified', 'Source: United Nations Conference on Trade and Dev'],
	PRIMARY KEY ("Countrycode", "Seriescode", "Year"), 
	CONSTRAINT fk_footnotes_series FOREIGN KEY("Seriescode") REFERENCES "Series" ("SeriesCode"),
	CONSTRAINT fk_footnotes_country FOREIGN KEY("Countrycode") REFERENCES "Country" ("CountryCode")
)


CREATE TABLE "Indicators" (
	"CountryName" TEXT -- example: ['Caribbean small states', 'Arab World'],
	"CountryCode" TEXT NOT NULL -- example: ['ABW', 'ADO'],
	"IndicatorName" TEXT -- example: ['Adolescent fertility rate (births per 1,000 women ', 'Age dependency ratio (% of working-age population)'],
	"IndicatorCode" TEXT NOT NULL -- example: ['AG.LND.AGRI.ZS', 'AG.LND.AGRI.K2'],
	"Year" INTEGER NOT NULL -- example: ['1961', '1962'],
	"Value" INTEGER -- example: ['87', '133'],
	PRIMARY KEY ("CountryCode", "IndicatorCode", "Year"), 
	CONSTRAINT fk_indicators_country FOREIGN KEY("CountryCode") REFERENCES "Country" ("CountryCode")
)


CREATE TABLE "Series" (
	"SeriesCode" TEXT NOT NULL -- example: ['AG.AGR.TRAC.NO', 'AG.CON.FERT.PT.ZS'],
	"Topic" TEXT -- example: ['Economic Policy & Debt: Balance of payments: Capit', 'Economic Policy & Debt: Balance of payments: Curre'],
	"IndicatorName" TEXT -- example: ['Foreign direct investment, net inflows (% of GDP)', 'Foreign direct investment, net (BoP, current US$)'],
	"ShortDefinition" TEXT -- example: ['', 'Total external debt is debt owed to nonresidents r'],
	"LongDefinition" TEXT -- example: ['Foreign direct investment refers to direct investm', 'Foreign direct investment are the net inflows of i'],
	"UnitOfMeasure" TEXT -- example: ['', '`'],
	"Periodicity" TEXT -- example: ['Annual'],
	"BasePeriod" TEXT -- example: ['', '2005'],
	"OtherNotes" INTEGER, 
	"AggregationMethod" TEXT -- example: ['', 'Weighted average'],
	"LimitationsAndExceptions" TEXT -- example: ['', 'FDI data do not give a complete picture of interna'],
	"NotesFromOriginalSource" TEXT -- example: ['', 'Estimates are presented with uncertainty intervals'],
	"GeneralComments" TEXT -- example: ['Note: Data starting from 2005 are based on the six', 'Note: Data are based on the sixth edition of the I'],
	"Source" TEXT -- example: ['International Monetary Fund, International Financi', 'International Monetary Fund, Balance of Payments S'],
	"StatisticalConceptAndMethodology" TEXT -- example: ['', 'Data on equity flows are based on balance of payme'],
	"DevelopmentRelevance" TEXT -- example: ['', 'Private financial flows - equity and debt - accoun'],
	"RelatedSourceLinks" TEXT -- example: ['', 'World Bank, PovcalNet: an online poverty analysis '],
	"OtherWebLinks" INTEGER, 
	"RelatedIndicators" INTEGER, 
	"LicenseType" TEXT -- example: ['Restricted', 'Open'],
	PRIMARY KEY ("SeriesCode")
)


CREATE TABLE "SeriesNotes" (
	"Seriescode" TEXT NOT NULL -- example: ['DT.DOD.PVLX.CD', 'IC.CUS.DURS.EX'],
	"Year" TEXT NOT NULL -- example: ['YR2002', 'YR2014'],
	"Description" TEXT -- example: ['Interpolated using data for 1957 and 1962.', 'Interpolated using data for 1957 and 1962, if the '],
	PRIMARY KEY ("Seriescode", "Year"), 
	CONSTRAINT fk_seriesnotes_series FOREIGN KEY("Seriescode") REFERENCES "Series" ("SeriesCode")
)

Question: Which country has the smallest land area in square kilometers for 19 consecutive years starting from year 1961? Indicate how much is its land area in square kilometers in those years and the income group of the country.
Evidence: the smallest land area in square kilometers refers to min(value where IndicatorName like 'Land area (sq. km)'); for 19 consecutive years starting from year 1961 refers to Year between 1961 and 1979

SQL:
SELECT T1.CountryName, SUM(T1.Value) area, T2.IncomeGroup FROM Indicators AS T1 INNER JOIN Country AS T2 ON T1.CountryCode = T2.CountryCode WHERE T1.IndicatorName = 'Land area (sq. km)' AND T1.Year >= 1961 AND T1.Year < 1980 GROUP BY T1.CountryCode ORDER BY SUM(T1.Value) ASC LIMIT 1