Had a few moments to kill...

USE tempdb

GO

-- It's always good to provide sample data in an easily usable format like so

CREATE TABLE dbo.

([year] int not null,

Client_Name varchar(100) not null,

Product_Name varchar(100) not null);

INSERT dbo.

VALUES

(2014,'Bob','Hosting'),

(2014,'Bob','Development'),

(2014,'Bob','Testing'),

(2014,'Fred','Development'),

(2014,'Fred','Consulting'),

(2014,'Max','Consulting'),

(2015,'Bob','Hosting'),

(2015,'Bob','Testing');

-- Solution that Luis suggested from http://www.sqlservercentral.com/articles/comma+separated+list/71700/

WITH ClientByYear AS

(

SELECT [year], Client_Name

FROM dbo.

GROUP BY [year], Client_Name

)

SELECT

[year],

Client_Name,

list = STUFF

((

SELECT '-' + Product_Name

FROM dbo.

t

WHERE c.[year] = t.[year] AND c.Client_Name = t.Client_Name

ORDER BY Product_Name

FOR XML PATH(''), TYPE).value('.','varchar(max)'),1,1,'')

FROM ClientByYear c;