Former substitute teacher Mary Sheehan, who retired in December 2017, saved $1,933 toward a pension over 1 years working for public schools, Chicago Teachers' Pension Fund records show.

Over 30 years of retirement, Sheehan would collect as much as $92,720, according to a projection by Local Government Information Services (LGIS), which publishes Chicago City Wire.

The projection assumes Sheehan received $1,948 in the first year of retirement, then 3 percent annual increases thereafter, compounded.

After 1 years of retirement, Sheehan will have already received $1,948 in retirement benefits, or more than the sum total of the retiree's contributions to the teachers' pension fund.