How many countries have notes on the indicator Stocks traded, turnover ratio of domestic shares?
indicator Stocks traded, turnover ratio of domestic shares refers to IndicatorName = 'Stocks traded, turnover ratio of domestic shares (%)'
SELECT COUNT(T1.Countrycode)  FROM CountryNotes AS T1 INNER JOIN Series AS T2 ON T1.Seriescode = T2.SeriesCode WHERE T2.IndicatorName = 'Stocks traded, turnover ratio of domestic shares (%)'