Hello Dear. IRCC send 23,100 Invites to fill in 15,000 spots. Approximately 155,313 people applied to receive the Invites. After filling in 15,000 spots there will still be ( 155,313-15,000 = 140,313 ) applicants leftover in the previous pool. As we all know that IRCC is not accepting any more Interests to sponsor for the last couple of years. Looks like they want to clear the backlog. Simple mathematic calculation reveals that it will take (140,313/ 15,000) = 9.4 ............which is approximately 9 years from now till they start accepting more Interests unless IRCC increases the intake from 15,000 to a bigger figure.
Best would be to call your Parents on Super Visa.