group               model steps   single    twice
APS                        1275    21.6%     8.7%
CHA fun1                     47    17.0%     4.3%
CHA flat fun3-6            1251    53.6%    27.8%
CHA fun7                      0     0.0%     0.0%
CHA other                   174    36.2%    20.7%

T1 twice: flat 27.8% > APS 8.7% and > fun1 4.3%  ->  PASS
T2 flat/APS ratio: twice 3.20 vs single 2.47  ->  PASS