Conversation so far:
who has won the australian grand prix this year?
Valtteri Bottas won the australian grand prix in 2019.
what team is Valtteri Bottas?
2019 team. Mercedes.
what nationality is Valtteri Bottas?
Finnish

Question: how long is the Mercedes team tenure?
Self-contained rewrite: how long is the Mercedes team tenure of Valtteri Bottas?