Well first your calculation for the total number of GB written is a little off. The number listed 156675645 is the total number of write operations issed by the host. Each write operation is done in 512bytes. To get the total GB written use the following method.
Number of total write operations x 512 = total number of bytes written
156675645 x 512 = 80,217,930,240
Total number of bytes written / 1,024 = total number of kb written
80,217,930,240 / 1,024 = 78,337,822
Total number of kb written / 1,024 = total number of MB written
78,337,822 / 1,024 = 76,501
Total number of MB written / 1,024 = total number of GB written
76,501 / 1,024 = 74.7
So actually you have only written about 75GB to the drive. Now is 75GB of data written on the high side? Yes, however this is not abnormal. The first few weeks or so after the software has been installed Expresscache will be learning your usage patterns. During this learning period is when you will see the most writes to the SSD. Since it does not yet know your usage patterns all LBAs read will be cached. As the Expresscache software learns your usage patters only the LBAs that have been read at a high frequency will be kept in the cache.
Now let’s address file selection for caching. The ExpressCache software does not cache at the file of folder level. ExpressCache caches LBAs. The software does not know what data is contained in the LBAs so there is no way to select what you want cached. ExpressCache only monitors the LBA for high frequancy reads and caches those LBAs.
The Expresscache software will need some time to learn your usage patterns. After it determins high usage of certine LBAs they will be given priority and not be flushed from the cache. In the begining and until it learns your usage patterns it will cache any LBAs read and flush the cache as needed.
Another factor is that you have had 3 unexpected power losses. Anytime there is an unexpected power loss it can cause the cache to not be in sync with the HD. Anytime this occurs the cache will be flushed.
All this said even at the current usage rate the drive would last at least 3 years which is the warranty period. The usage should slow down once your usage patterns are learned by the Expresscache software.