updated rescaling: only for retrospective scenarios

this doesn't actually change the scores since Greenland 2010 is the max:

```
eez2014 pressures scores are rescaled to maximum 'poopers' since eez2012 (2010-2012):
Greenland in 2010

eez2013 pressures scores are rescaled to maximum 'poopers' since eez2012 (2010-2011):
Greenland in 2010

eez2012 pressures scores are rescaled to maximum 'poopers' since eez2012 (2010-2010):
Greenland in 2010
```