Exponential Armor Class

Level	KXP	Effect
1	0.3	+1 AT
2	0.6	+4 AT
3	1.2	+9 AT
4	2.4	+16 AT
5	4.8	+25 AT
6	9.6	+36 AT
7	19.2	+49 AT
8	38.4	+64 AT
9	60	+81 AT
10	90	+100 AT
11	120	+121 AT
12	150	+144 AT
13	180	+169 AT
14	210	+196 AT
15	240	+225 AT
16	270	+256 AT
17	300	+289 AT
18	330	+324 AT
19	360	+361 AT
20	390	+400 AT
21	420	+441 AT
22	450	+484 AT
23	480	+529 AT
24	510	+576 AT
25	540	+625 AT
26	570	+676 AT
27	600	+729 AT
28	630	+784 AT
29	660	+841 AT
30	690	+900 AT
31	720	+961 AT
32	750	+1024 AT
33	780	+1089 AT
34	810	+1156 AT
35	840	+1225 AT
36	870	+1296 AT

Each level you take in this overwrites the previous levels bonus to AT.