Like I said, I've read the above official link. Multiple times, by now. Nowhere do I see a reference to the habitual language. Only to the Primera Llengua, which is

Llengua o llengües que la persona ha parlat primer a casa seva. Es considera que aquesta llengua ha estat transmesa familiarment i adquirida en el procés de socialització de l'individu.

This is not the habitual language. So, where is it?

The above official link has many sections. Here is the link for the official language poll ("Enquesta d’usos lingüístics de la població 2008"), which includes mother-initial/identification/habitual language details (official data):

http://www.idescat.cat/cat/idescat/publicacions/cataleg/pdfd...

"Initial language" (page 45):

Catalan: 31.6%, Spanish: 55%.

"Identification language" (page 48):

Catalan: 37.2%, Spanish: 46.5%

"Habitual language" (page 51):

Catalan: 35.6%, Spanish: 45.9%

Edit: in my first comment in this thread I spoke from memory. Also, the data from the 2013 poll (official data):

https://www.idescat.cat/cat/idescat/publicacions/cataleg/pdf...

"Initial language" (page 45):

Catalan: 31%, Spanish: 55.1%.

"Identification language" (page 46):

Catalan: 36.4%, Spanish: 47.5%.

"Habitual language" (page 49):

Catalan: 36.3%, Spanish: 50.7%.

Thank you!

EDIT: Seems like that's the old poll. There's a new one from 2013, in which both Catalan and Spanish grew as the habitual languages. It still doesn't reach 55%, though.