The table  below shows the natural growth rate of the population of country N over a  period of time.
 Use the information  contained in the table to answer  the  following questions.             
                        
                          
                            | Year | Birth Rate per’000 | Death Rate per ‘000
 | Natural Growth Rate | 
                          
                            | 1971 | 45 | 32 | L | 
                          
                            | 1972 | 39 | P | 12.50 | 
                          
                            | 1973 | 26 | 22 | Q | 
                          
                            | 1974 | R | 22.50 | 4.50 | 
                          
                            | 1975 | 26.50 | 22.50 | S | 
                          
                            | 1976 | 20.50 | T | 3.00 | 
                        
                        (a) Determine L,P,Q,R,S, and T.
                        (b) With the use of a bar chart, graphically present the  changes in the natural growth rate over the years. (Use of graph sheet is  essential) 
                        (c) Outline any three reasons for changes in birth rate.