As a Challenge cache you will need to list in your Found It log entry the NINE (9) caches from 'your state' that qualify you for the 'Specialist' Find here. (Obviously) They are all of the rating of Difficulty 3½, and the Terrain ratings required are: T1, T1½, T2, T2½, T3, T3½, T4, T4½, and T5.
As the cache is NOT at the above coordinates, rather, it is at S31º 's' E152º 'e', where the minutes of this Challenge cache are:

Rules:
1/ The particular consecutive 2 Years, or TWENTY FOUR consecutive MONTHS is the frame that you select. So it could be from the first two years that you started, OR, the most recent consecutive 24 months, OR any consecutive years in between. This DOES NOT have to correlate with any of the months required for other in the Nine Tree Trail Series.
2/ This could be extended by a further TWELVE MONTHS for each additional different Type of cache you are able to include in your list. SO, if you only use one particular Type of cache (no matter WHAT Type it is) it is still up to you to select the particular 2 years to get your list of caches from. BUT, if you choose (or are able) to include, say, x 4 different Types of caches in your list each with a unique Terrain rating then you could have 5 years in the past of logging this cache to gain your list from - for example only.
3/ In your Found It log (or Note, if getting ready to come and find it), please include your State of Origin, and the time frame you are using for this cache. Then, for each of the x 9 qualifying caches: Terrain rating, GC code, Cache Name, Type, Date Found.
re 3/ a) Alternate ways to show qualifying caches, 4/ 'Wildcard', and 5/ Cache Owner exceptions see the D1 x 9 T State Challenge, GC5D8TN.
Below is a statistical representation of the quantity of Difficulty 3½ caches that were active in the Australian States in September, 2014. As can be seen the ACT, Northern Territory, and Tasmania don't have a full complement of D3½ caches, so any 'bordering state'* could be chosen for those missing Terrain combinations, and your State of Origin would still be accepted. PLEASE DON'T take these numbers 'as Gospel', as we all know that new caches will be added, and others Archived.

New South Wales: 1/1/13 to 30/4/14 (x 3 Types -> 2 years)
T1, GC41TYJ, Mini-Manning MAP's Challenge, Unknown, 18/5/13
1½ GC40QPG, Stumped Series #6: Stumped on Mangrove Mountain, Multi, 22/6/13
T2, GC2V149, Vimiera, Trad, 24/6/13
2½ GC1VM9J, Pot Luck!, Trad, 12/12/13
T3, GC4EGCW, Quarry Quizzer, Unknown, 28/6/13
3½ GC102GC, Air, Trad, 15/11/13
T4, GCMFMW, Blue Hole, Multi, 4/8/13
4½ GC1PHKG, 4X4 Pass, Trad, 11/1/13
T5, GC4ZNYD, Dinosaurs must die, Trad, 5/4/14
*For Taswegians, the 'neighbouring state' could be Victoria or even South Australia - at a stretch. ** For all states, IF you own a cache that was published before this cache was published, and it is in a Light Blue, or White Sector for your State you are able to use your cache for that particular D/T combination. And no need to use a 'Wildcard' for that. THANKS very much for adding to the variety.