A comparison was made between cultivation in the past in 1900 and the present time. Where it was found that in the year 1900, 40% of the workers were working in the field of agriculture, and farmers were producing per day enough food for an average of 5 people, for themselves and their families, and working manually. But at the moment there is much more equipment, machinery and production.
The word "themselves" in Paragraph (1) refers to