I'm trying to automate a spreadsheet that has a list of trucks and another
list of depots that are used each month but sometimes not all are used or a
new depot or a new truck turns up, I want my spreadsheet to reflect this or
else it doesn't balance and requires manual work to identify what's new or
what's old and won't appear again.

One month there may be 100 trucks used but the next there might be 90 or
110. Vehicle reference numbers for the trucks are known but there are 999
truck codes even though there may only be 200 trucks in use. A lot of vacant
reference numbers. I thought that if I had a spreadsheet that takes the raw
data on one worksheet and vlookup that data to a truck worksheet, this would
solve my problems but would need to have 999 rows which with only 200 trucks,
I thought there must be a better way.

Any ideas how best to deal with this?