Table: us_grand_prix_2002
Columns: driver
constructor
laps
time_retired
grid

Question: What is the Time/Retired that has a Grid smaller than 8, 73 laps, and a Constructor of williams - bmw?
SQL: SELECT "time_retired" FROM us_grand_prix_2002 WHERE "grid" < 8 AND "laps" = 73 AND "constructor" = 'williams - bmw'