What portion of the nations in Latin America and the Caribbean had more than 50% of their land used for agriculture in 1961?
portion = divide(count(CountryName where Year = '1961' and Value>50), count(CountryName))*100%; nations in Latin America and the Caribbean refers to region = 'Latin America & Caribbean';  more than 50% of their land used for agriculture refers to value where indicatorname = 'Agricultural land (% of land area)'>50; in 1961 refers to Year = '1961'
SELECT CAST(SUM(CASE WHEN T1.Value > 50 THEN 1 ELSE 0 END) AS REAL) * 100 / COUNT(T2.CountryCode) FROM Indicators AS T1 INNER JOIN Country AS T2 ON T1.CountryCode = T2.CountryCode WHERE T1.Year = 1961 AND T2.Region = 'Latin America & Caribbean' AND indicatorname = 'Agricultural land (% of land area)'