Name______________________________________________________________Period______________ Chapter 2-Population Key Issue 2: Where has the World?s Population Increased? Rubenstein, pp. 53-55 1. Define each of the following: a. crude birth rate (CBR) Crude birth rate is the total number of live births in a year for every 1,000 people alive in the society. b. crude death rate (CDR) Crude death rate is the total number of deaths in a year for every 1,000 people alive in the society c. natural increase rate (NIR) Natural increase rate is the percentage by which a population grows in a year. NATURAL INCREASE 2. What is the NIR today? 1.2 3. When did global NIR peak, what was it? 1963, 2.2%