Newfoundland has a lower population than Wyoming (the smallest US state by population), and PEI has just over 1/4 of NFLD. Mind you Wyoming still has more representatives per capita than NFLD.
Population of Newfoundland has remained steady at about 520,000 people, the exact same amount the Province had in 1970. In the same time frame, Alberta has increased its population from about 1,600,000 in 1970 to over 4,300,000 today.
For those interested, here is a link to Provincial populations, ending in the first quarter of 2019:
https://www150.statcan.gc.ca/t1/tbl1/en/tv.action?pid=1710000901