NAIROBI: Last year was challenging for the Nairobi Securities Exchange. The NSE 20 share index contracted by 21 per cent from 5,112 points in December 2014 to 4,040 points in December 2015. The All Share index similarly fell 19 per cent from 177 points in February 2015 to close at 145 points in December 2015 eroding the overall 6 per cent gain year-on-year compared to 2014.