Girando com a função Soma no tsql

Tenho dados no seguinte formato

Client       Business Unit    Year  Quarter     USD Amt
BalckRock    Pricing          2010  Q1          234
BalckRock    Pricing          2010  Q2          343
BalckRock    Pricing          2010  Q3          545
BalckRock    Pricing          2010  Q4          5435
BalckRock    Pricing          2011  Q1          5425
BalckRock    Pricing          2011  Q2          3524
BalckRock    Pricing          2011  Q3          54
BalckRock    Pricing          2011  Q4          5425
BalckRock    Pricing          2012  Q1          545
BalckRock    Pricing          2012  Q2          5445
BalckRock    Pricing          2012  Q3          545
BalckRock    Pricing          2012  Q4          4545
BalckRock    Sales            2010  Q1          23
BalckRock    Sales            2010  Q2          3434
BalckRock    Sales            2010  Q3          4234
BalckRock    Sales            2010  Q4          4234
BalckRock    Sales            2011  Q1          3423
BalckRock    Sales            2011  Q2          1
BalckRock    Sales            2011  Q3          1341
BalckRock    Sales            2011  Q4          434
BalckRock    Sales            2012  Q1          421
BalckRock    Sales            2012  Q2          42
BalckRock    Sales            2012  Q3          434
BalckRock    Sales            2012  Q4          4214

E eu quero no seguinte formato

Client        Business Unit    2010    2011    2012
BalckRock     Pricing          6557    14428   11080
BalckRock     Sales            11925   5199    5111

Basicamente a soma do USD no ano, mas anos como o título da coluna

Alguém pode me ajudar com isto ?