I have a table with Columns as City, Year and Population Growth of City relative to previous Year. I want to create animation in bubble chart in which size of bubble represents poplation of a city corresponding to different Years. Since, I just have the population growth instead of total population till a particular year stored in the table, I would want to add the Growth number of previous years so as to give an animation with increasing bubble's size. Size of bubbles represents population, which increases with time. And different bubbles represent different cities. Please help me in writing the expression for calculating the sum of all previous years population growth dynamically during animation.
Table looks like this. Assume the population of Cities before 2001 was 0
| Year | City | Increase in Population |
|---|
| 2001 | A | 1000 |
| 2001 | B | 2000 |
| 2001 | C | 1500 |
| 2002 | A | 1500 |
| 2002 | B | 1600 |
| 2002 | C | 2000 |
| 2003 | A | 1800 |
| 2003 | B | 2500 |
| 2003 | C | 1700 |
Bubble size for City A should depict 1000 for year 2001, (1000 + 1500 = 2500) for year 2002 and so on for all cities.
Problem is, how to calculate sum of all previous years' values. PLEASE HELP....!!!!
