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, which only has 9 numbers. We will still call it a decade.
The numbers extracted are distributed into 1, 2, 3, 4, 5 decades. Generally, in 4 decades, but whoever wants a higher reduction can go to 3 decades.
The chart displays the combinations with the number of decades 1, 2, 3, 4, 5 on the abscissa, and a column shows how many times the respective combination was extracted, next to each combination (the number is displayed above).