Finalisation of the data structure

[HenryQuan]

The current structure can change at any time. Before merging our changes back to master, we should stabilise the data structure to prevent future changes unless it is required. It is also a good idea to keep track of the current structure in a README or somewhere. It is always fine to add new entries. However, modifying an entry will require lots of changes in the app layer. We should keep that in mind especially when app gets more complex.

• Missing data #14
• Cast number to int or float explicitly  #12
• Handle new data #15

[HenryQuan]

The structure is still not finalised. I will spend some time this weekend to possibly finish this.