University biology - Relative water content help?

I'm a biology fresher on the BR12920 - vegetation and ecosystems module with an assignment due in a week for a lab report on comparing RWC in 3 different plants. My issue is that I don't understand what I'm looking for? I have all these results showing differing RWC's but what does it mean? Does a higher RWC correlate to a higher survivability in drought?Why am I getting higher RWC's in drought plant species compared to their fresh water daily plant species?

Frantic googling and reading has failed me.