Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE InvoiceLine ( InvoiceLineId integer, InvoiceId integer, TrackId integer, UnitPrice decimal(10,2), Quantity integer )
TABLE: CREATE TABLE PlaylistTrack ( PlaylistId integer, TrackId integer )
TABLE: CREATE TABLE MediaType ( MediaTypeId integer, Name varchar(120) )
TABLE: CREATE TABLE Invoice ( InvoiceId integer, CustomerId integer, InvoiceDate datetime, BillingAddress varchar(70), BillingCity varchar(40), BillingState varchar(40), BillingCountry varchar(40), BillingPostalCode varchar(10), Total decimal(10,2) )
TABLE: CREATE TABLE Employee ( EmployeeId integer, LastName varchar(20), FirstName varchar(20), Title varchar(30), ReportsTo integer, BirthDate datetime, HireDate datetime, Address varchar(70), City varchar(40), State varchar(40), Country varchar(40), PostalCode varchar(10), Phone varchar(24), Fax varchar(24), Email varchar(60) )
TABLE: CREATE TABLE Genre ( GenreId integer, Name varchar(120) )
TABLE: CREATE TABLE Customer ( CustomerId integer, FirstName varchar(40), LastName varchar(20), Company varchar(80), Address varchar(70), City varchar(40), State varchar(40), Country varchar(40), PostalCode varchar(10), Phone varchar(24), Fax varchar(24), Email varchar(60), SupportRepId integer )
TABLE: CREATE TABLE Track ( TrackId integer, Name varchar(200), AlbumId integer, MediaTypeId integer, GenreId integer, Composer varchar(220), Milliseconds integer, Bytes integer, UnitPrice decimal(10,2) )
TABLE: CREATE TABLE Artist ( ArtistId integer, Name varchar(120) )
TABLE: CREATE TABLE Playlist ( PlaylistId integer, Name varchar(120) )
TABLE: CREATE TABLE Album ( AlbumId integer, Title varchar(160), ArtistId integer )

### Question ###
What are the first names and support rep ids for employees serving 10 or more customers, and could you list total number in descending order please?

### Accurate SQL ###

SELECT T1.FirstName, T1.SupportRepId FROM Customer AS T1 JOIN Employee AS T2 ON T1.SupportRepId = T2.EmployeeId ORDER BY T1.SupportRepId DESC