According to the plural forms definition from gnu, the plural form for French language is for everything > 1 (0 and 1 are not pluralized).

Everything below 2 is not pluralized in French language, in case of non-integer counting, you will write 1,5 objet not 1,5 objets.

Two forms, singular used for zero and one Exceptional case in the
language family. The header entry would be:

Plural-Forms: nplurals=2; plural=n>1;

Languages with this property include:

• Romanic family: Brazilian Portuguese, French

In English, only 1 is not pluralized, 0 and n > 1 are pluralized.

Two forms, singular used for one only This is the form used in most
existing programs since it is what English is using. A header entry
would look like this:

Plural-Forms: nplurals=2; plural=n != 1;

Languages with this property include:

• Germanic family: English, German, Dutch, Swedish, Danish, Norwegian, Faroese
• Romanic family: Spanish, Portuguese, Italian, Bulgarian
• Latin/Greek family: Greek
• Finno-Ugric family: Finnish, Estonian
• Semitic family: Hebrew
• Artificial: Esperanto
• Finno-Ugric family: Hungarian
• Turkic/Altaic family: Turkish

In French we use the singular for all quantity that is below 2.
This means that even 1.5, for us, is singular:

Il y a deux sites web.
Il y a un site web.
Il y a zéro site web.
Il y a un site web et demi (si le second n’est pas fini :)).

Ou encore

Il y a 2 sites web.
Il y a 1 site web.
Il y a 0 site web.
Il y a 1,5 site web.

More details here (first section of the document).