Operation of WPP[edit] WPP is run prior to compilation (in other words, before even the C preprocessor), and generates a trace message header for each file that it processes (by default this header is filename.tmh, where filename is the name of the processed source file). WPP's understanding of C/C++ syntax is very limited.
Divide the new value by the old value and multiply by 100 to find the absolute relationship between the two values. A process that is similar (but not identical) to the process used to find percent change is that used to find the absolute percentage relationship between the old and new values.
7. Subtract 100 from the new result to find the change in CPI. By doing this, you are subtracting the baseline--represented by the number 100--to determine the change over time. 1  Again, using the above example, the result would be 12.5, representing a 12.5% change in prices from the first period to the second.