Citigroup's net income increased to $3.6 billion in the fourth quarter 2016, primarily driven by the lower operating expenses and cost of credit, partially offset by lower revenues. Citigroup's effective tax rate was 30% in the current quarter compared to 29% in the fourth quarter 2015.
Mercosur, or the Southern Common Market, is a customs union between Brazil, Argentina, Uruguay and Paraguay. It was originally set up in 1991. Bolivia, Chile, Colombia, Ecuador and Peru have associate member status. Bolivia may be incorporated as a full member soon.
Menarche is the start of the first menstrual period. Menarche has occurred at a younger age during the last century. This may be due to improved nutrition (and subsequent weight) in the population. The average age of menarche is 13 years but it can be as early as 8 years and as late as 16 years and still be normal.