Formula to return most recent instance of value?

Hello!
I am attempting a cleanup of five fields in our animal shelter software, called Chameleon. For instance, one of the fields in Chameleon is Intake Type. In that field, the user must choose one of 12 different options such as stray, owner surrender, etc. for the animal in question. I'd like to know which of the 12 options have not been chosen by any users in the last five years, so I can delete the options that no one is using.

I exported about 5 years of data from the software and included the intake date, which is about equal to the date last used for all fields being looked at. In the first tab is the last 5 years' data, called 2011-2016_Orig. The next tab is named after the fields, and contain the distinct options in each field- each option is shown once. So in Intake_Type there are 12 different choices a user can make. I'd love to be able to see the most recent date each option was used so I can see which options have not been used in a long time.

Is there a VLOOKUP formula or something similar I can use to find the date each value in column A on tab two appears in tab one's data set? So for instance, what is the most recent date an animal was recorded as Stray in tab one Column B?

Any help that can be offered is GREATLY appreciated, thank you for your help in advance!!

Melissa

Put this array* formula in B2 of Sheet2:

=MAX(IF('2011-2016_Orig'!$B$2:$B$16628=A2,'2011-2016_Orig'!$A$2:$A$16628))

Format the cell as a date, then copy down. Note the final 3 return zero as they are not present in your other sheet - this is interpreted by Excel as the zeroth of January 1900.

*An array formula needs to be committed using the key combination of Ctrl-Shift-Enter (CSE), instead of the usual < Enter >.

Hope this helps.

Pete

This works perfectly, thank you so so much!