pattern possibility #4

4. my sister knew her husband for 1 year before marrying. my brother knew his wife for 5 years before marrying. it would then follow that i would know my husband 9 years before marrying.

unless the pattern isn't an addition of 4 years, but rather the multiplication of 5... in which case it would follow that i would know my husband 25 years before marrying. i'm 25 now... that could happen, i suppose.