RANK results in kibana

Hello,

On kibana 7.4

Please condsider the following case:

I have a json file with 3 column :

STUDENT DATE GRADE
A 01/02/2020 80
A 11/01/2020 85
A 25/01/2020 83

B 01/02/2020 88
B 11/01/2020 81
B 25/01/2020 81

C 01/02/2020 98
C 11/01/2020 91
C 25/01/2020 97

I have created a Kibana TABLE visualization which show the results.

Now i need to complete two tasks :

  1. To mark if the most current grade per student is the highest
    (i.e: 80=NO , 88=YES , 98=YES)

  2. To count how many students improve there results
    (i.e : The count should return : 2 )

Any advise how to do it ?

Thanks
Yoav