We divide all the numbers from 1 to 49 into 5 groups of 10 numbers each called decades.
1, 2, 3, 4, 5, 6, 7, 8, 9, 10
11, 12, 13, 14, 15, 16, 17, 18, 19, 20
21, 22, 23, 24, 25, 26, 27, 28, 29, 30
31, 32, 33, 34, 35, 36, 37, 38, 39, 40
41, 42, 43, 44, 45, 46, 47, 48, 49
Each group has 10 numbers except for the last group 41-49 that has only 9 numbers. We will still call it a decade.
The numbers extracted are distributed in 1, 2, 3, 4, 5 decades. Generally, in 4 decades, but whoever wants a higher reduction can go to 3 decades.
The graph displays on the abscissa the combinations with the number of decades 1,2,3,4,5, and beside each combination, a column shows how many times the respective combination was extracted (the number is displayed above).