In 1970, how many Middle Eastern & North African countries whose value for CO2 emissions from gaseous fuel consumption (kt) indicator is more than 600?
Year = 1970; Middle East & North Africa is the name of the region where Region = 'Middle East & North Africa'; CO2 emissions from gaseous fuel consumption (kt) is the name of indicator where IndicatorName = 'CO2 emissions from gaseous fuel consumption (kt)'
SELECT COUNT(T2.CountryCode)  FROM Indicators AS T1 INNER JOIN Country AS T2 ON T1.CountryCode = T2.CountryCode WHERE T2.Region = 'Middle East & North Africa' AND T1.IndicatorName = 'CO2 emissions FROM gaseous fuel consumption (kt)' AND T1.Year = 1970 AND T1.Value > 600