In regards to the questions about which data sets you should know:
2011 and 2016 are the most important. The syllabus is asking for the CURRENT religious landscape. As mentioned in the threads, it's great to know some other key dates for the purpose of comparison of significant events, like when Catholicism overtook Anglicanism, or when No Religion overtook Catholicism (2016). The only thing I'd ever reference 1901 for is to say that the Jewish population then is the exact same in percentage as it is now, thus making it the steadiest religious adherence in Australia. So I'd focus on knowing the most recent census data the most, but then there is relevance for knowing some other key dates from the 20th century (or 2001 and 2006 data sets) as well. 
I have ALSO uploaded a chart with all of the key census data from 1901 to 2011 for free download here so that will be helpful! 
(There's also a copy of this in the AN SOR note book!)
Thanks for your contributions Dancing Phalanges! 
Hey Elyse just with No Religion - does that include new age religions or does that come under not stated/unclear?

Just in terms of when I discuss no religion in whether I tie it in with new age religions as well!
Wait, so what are the key principal beliefs for christianity?
Back to prelim studies! For Christianity these are them and the notes I had:
Principal Beliefs
DIVINITY AND HUMANITY OF JESUS CHRIST - Result of the Nicene Creed
- Controversial topic in the 4th and 5th century
- Docetism undermined the idea of the humanity of Jesus and rather argued Jesus to be fully divine and not truly human but merely adopting the appearance of a human.
- Arianism believed Jesus to be superior to the rest of creation but not equal to God as he is a product of God.
- 325 Council of Nicea claimed Jesus to be fully divine.
- “Who do people say the Son of Man is?” Matthew 16:13-20 (claiming sonship was tantamount to claiming equality to God> therefore divine.
DEATH AND RESURRECTION OF JESUS- Christians have typically believed Jesus died for our sins.
- Questions why God would appease of the execution of an innocent man
- A more adequate reflection is that death is an integral part of human condition and is one which shared by Jesus.
- Death of jesus = unconditional love of God
- “if we have faith in Jesus and God and his death we shall also live an eternal life” > salvation through faith in Jesus
NATURE OF GOD AND THE TRINITY- God is one existing in three persons
- Gods promise of salvation is fulfilled through the life death and resurrection of Jesus and the outpouring of the Holy Spirit
- God the Father is revealed in the Hebrew Scriptures
- God the Son is revealed in the Christian Scriptures
- God the Spirit is revealed in the Church
- Matthew 28:19 therefore go and make disciples of all nations baptising them, in the name of the father, the son and he holy spirit.”
- Holy trinity is beyond human understanding as is revealed through revelation through God
- The father is transcendent (beyond the world) the son is immanent (involved in the world) while the spirit comes from God and is both immanent (within the being) and transcendent (comes from god)
Revelation- refers to a disclosure by God of what was previously unknown
Christianity Judaism and islam claim to be revealed religions
Christians see christs incarnation, life, death and resurrection and sending of the holy spirit the climax of the process of divine self disclosure.
John 3.34 for the one who god has sent speaks the word of God > jesus as revelation
Johns gospel richest source of revelation
SalvationDelivered from suffering
Role of god in salvation is decisive
Draws from moses and the exodus
Gods saving action has a particular emphasis on the vulnerable
Jesus embodies the saving action of god in the resurrection
“Salvation is achieved through faith in jesus, whose death reflects God’s saving action and love of human kind.”