I wonder in the individual income tax law, how to calculate the accrual basis for prepaid income.?

For example:

Orange Apartments, an accrual basis taxpayer, allows its renters to pay by the year in advance ($500 per year), or two years in advance ($950). In September 2016, the company collected the following amounts applicable to future services:

October 2016-September 2018 services (two-year contracts) $144,000

October 2016-September 2017 services (one-year contracts) 128,000

Total $272,000

As a result of the above, Orange Apartments should report as gross income:

The calculation of gross income for 2016 is 144,000/24*3+128,000/12*3= 50,000

But for 2017, we have to calculate the gross income is 272,000-50,000=222,000 or 144,000/24*12+128,000/12*9=168,000

which one is correct for year 2017 gross income? why?