In this task, find the most appropriate number to replace the blank (indicated with _ ) and express it in words.

[EX Q]: New species are believed to arrive in the Mediterranean at the rate of _ to five annually.
[EX A]: four

[EX Q]: Rye grasses germinate in _ days.
[EX A]: six

[EX Q]: Russian banks have _ year history of embezzeling depositors money.
[EX A]:
ten