This section applies only to an allowance based on creditable service earned on or after July 1, 2011, for a former member, retiree, or surviving beneficiary of a deceased member, former member, or retiree of: the Correctional Officers’ Retirement System; the Employees’ Pension System; the Law Enforcement Officers’ Pension System; the State Police Retirement System; or the Teachers’ Pension System. A cost–of–living adjustment payable under this section shall be a compound cost–of–living adjustment computed in accordance with § 29–402(d)(2) of this subtitle. A cost–of–living adjustment payable under this section shall be subject to a cost–of–living rate cap of: 5% if, for the calendar year ending December 31 in the preceding fiscal year, the total investment performance of the several systems equals or exceeds the assumed rate of investment return established by the Board of Trustees in accordance with § 21–125(c) of this article and in effect as of December 31 of the preceding fiscal year; or 1% if, for the calendar year ending December 31 in the preceding fiscal year, the total investment performance of the several systems does not equal or exceed the assumed rate of investment return established by the Board of Trustees in accordance with § 21–125(c) of this article and in effect as of December 31 of the preceding fiscal year.