The purpose of this program is to improve the performance of a library processing CSV files. The aim is to make this code work faster and consume less memory.

1. Avoid storing null data into dictinaty to reduce memory consumption and loading performance
2. Reduce boxing and unboxing processes to reduce memory consumption and performance

Test results for old code: Memory increase in bytes: 215,347,984 Time of loading the CSV was 00:00:00.4630296. Time of reading the CSV was 00:00:00.4832441.

Test results for new code: Memory increase in bytes: 29,305,960 Time of loading the CSV was 00:00:00.0651940. Time of reading the CSV was 00:00:00.4711488.