After 40 testees, together with second norm report, I'll publish detailed statistical information about quality of each test.
   First of all, I give some notes and explain my procedure.

   S=number of points achieved by top 90% scorers on particular item
   R=the worst ranking among testees from previous step

   For each solved item I'll calculate the ratio S/R.
   This ratio would ideally be equal to 1, and otherwise less than 1.

   If this ratio will be lower than 0.6, item will be qualified as average.
   If this ratio will be lower than 0.4, item will be qualified as suspicious.
   If this ratio will be lower than 0.25, item will be qualified as bad.

   Quality will be calculated as average ratio.

IQ test
good items
average items
suspicious items
bad items
unsolved items
quality
FREE Fall            
LSHR
9
10
4
5
2
51,9%
LSHR Light
16
3
4
5
2
62,4%
LSHR Classic
14
12
7
3
0
55,4%
Numerus
10
4
11
5
0
46,4%
Numerus Light
23
5
1
1
0
79,7%
Numerus Classic
18
7
11
0
0
59,5%
Elementary            
Triplex            
Einplex            
HI-Qlass            

   These data will be updated after each 40 testees, up to 200 of them.

   CONCLUSION:
   Strong rules are presented here. In my opinion, tests with quality higher than 60% are what we are looking for in IQ world,
   and tests with quality lower than 35% should be avoided.