Search volume in adwords keyword tool

Hello,
I would like to know why the number of search volume by month is incorrect in adwords keyword tool.
For example if i type "date nyc" the number of search volume by month is 90 !!
Only 90 people searched for this keyword in the world ? (seem an average)
By the way do you know a free keyword analysis tool with normal search volume and number of results in google ?
Regards
Frank

See original post by luden