Count and group Marks by Student

[Sandet]

Hi
I have a this Table;

+-----------+--------------+------+---------------------+---------+-------+----------+-------+
| StudentID | AcademicYear | Term |     StudentName     |  Class  | Marks | Position | Count |
+-----------+--------------+------+---------------------+---------+-------+----------+-------+
|     12013 |         2015 | One  | Adamu A. Msangi     | Form IV |    80 |        1 |     5 |
|     52013 |         2015 | One  | Angela M. Lucas     | Form IV |    67 |        2 |     5 |
|     22014 |         2014 | Two  | Agness Daudi Martin | Form II |    60 |        3 |     5 |
|     32014 |         2014 | Two  | Agness John Missana | Form II |    51 |        4 |     5 |
|     42013 |         2015 | One  | Andrea F. Agustino  | Form IV |    50 |        5 |     5 |
+-----------+--------------+------+---------------------+---------+-------+----------+-------+
 

Which i have got by running the Sql Script below:

 SELECT * ,
ROW_NUMBER() OVER (ORDER BY Marks DESC) AS Position,  count(StudentID) OVER() AS 'Count'FROM Student

The output I'm looking for should show the student Position and Total number of Students. For example if I Query Student with ID No; 42013 and Term='One' and AcademicYear=2015 and Class='Form IV', I should get results similar with the following table:

+-----------+--------------+------+--------------------+---------+-------+----------+-------+
| StudentID | AcademicYear | Term |    StudentName     |  Class  | Marks | Position | Count |
+-----------+--------------+------+--------------------+---------+-------+----------+-------+
 
|     42013 |         2015 | One  | Andrea F. Agustino | Form IV |    50 |        5 |     3 |
 

Thanks

[Sandet]

Thanks I have solved it using this code

select *
from (
    select t.*, ROW_NUMBER() over (
            order by sum(Marks) desc
            ) as Position, count(StudentID) over (PARTITION BY term, class, academicyear) as Student_count
    from Student t    Group by StudentID, AcademicYear, Term, Class, StudentName, Marks
    ) t
 
where StudentID=42013