Complex sentence: Within seven years of its incorporation, i.e. by January 1996, JSE managed to list 750 companies and volume of daily turnover rose to average of Rs.80 million.
Split into simpler sentences: Within seven years of its incorporation, i.e. by January 1996, the exchange managed to attract 750 companies who were listed on the exchange. Then the volume of the daily turnover rose to an average of Rs.80 million.