The 2015 Davies report about gender diversity in UK boards increased the voluntary target for women at the biggest British companies to 33% by 2020, raising the previous objective of 25% by 2015. I attach the link to the full Davies report 2015.
According to the results, the voluntary approach in the UK seems to be working. As the report highlights, "Women’s representation on FTSE 100 boards now stands at 23.5%, almost double where we started at 12.5% in 2011. Furthermore, for the first time in the history of the London Stock Exchange, there are no all-male boards in the FTSE 100".
Against this background, there is a still a lively debate on the need for quotas and the possibility to broaden diversity beyond just gender.
Who is in the lead? Norway and Sweden are the countries with the highest proportion of females in the boards if we look at the main stock markets (35% in Norway´s OBX and 32,6% in Stockholm´s OMX 30). Please see The Guardian on Davies Report if you want to read more about this topic.