It's quite hard to consolidate multiple data sources in Excel, I did an example recently which made my eyes water. The easier way is to hav one big table onto which everybody's information is entered for all time, then use filtering and summarising tools, such as pivot tables to show subsets of that information.

If you could upload an example with several names (change them to protect privacy!) over several weeks, I can show you how to create two pivot tables to summarise that data very easily.

CC