Table: borje_jansson_1969
Columns: year
class
team
points
rank
wins

Question: What are the most wins in 1971 in 250cc class?
SQL: SELECT MAX("wins") FROM borje_jansson_1969 WHERE "class" = '250cc' AND "year" = 1971

Question: What is the earliest year with less than 45 points for Yamaha team in 21st rank?
SQL: SELECT MIN("year") FROM borje_jansson_1969 WHERE "points" < 45 AND "team" = 'yamaha' AND "rank" = '21st'