Nouns ending in -ance are feminine.
The suffix forms abstract nouns, often from verbs.
Is croissance masculine or feminine?
lacroissance
The rule behind it
100% of -ance nouns are feminine
In context
L'économie de ce pays est en croissance.
That country's economy is growing.
Nous savons comment l'alimentation influence la croissance.
We know how food affects growth.
Sarkozy a défendu un modèle de croissance durable.
Sarkozy defended a model of sustainable growth.