income tax liabilities tax liabilities related to unrecognized tax benefits as of 30 september 2018 were $ 233.6 . these tax liabilities were excluded from the contractual obligations table as it is impractical to determine a cash impact by year given that payments will vary according to changes in tax laws , tax rates , and our operating results . in addition , there are uncertainties in timing of the effective settlement of our uncertain tax positions with respective taxing authorities . however , the contractual obligations table above includes our accrued liability of approximately $ 184 for deemed repatriation tax that is payable over eight years related to the tax act . refer to note 22 , income taxes , to the consolidated financial statements for additional information . obligation for future contribution to an equity affiliate on 19 april 2015 , a joint venture between air products and acwa holding entered into a 20-year oxygen and nitrogen supply agreement to supply saudi aramco 2019s oil refinery and power plant being built in jazan , saudi arabia . air products owns 25% ( 25 % ) of the joint venture and guarantees the repayment of its share of an equity bridge loan . in total , we expect to invest approximately $ 100 in this joint venture . as of 30 september 2018 , we recorded a noncurrent liability of $ 94.4 for our obligation to make future equity contributions in 2020 based on our proportionate share of the advances received by the joint venture under the loan . expected investment in joint venture on 12 august 2018 , air products entered an agreement to form a gasification/power joint venture ( "jv" ) with saudi aramco and acwa in jazan , saudi arabia . air products will own at least 55% ( 55 % ) of the jv , with saudi aramco and acwa power owning the balance . the jv will purchase the gasification assets , power block , and the associated utilities from saudi aramco for approximately $ 8 billion . our expected investment has been excluded from the contractual obligations table above pending closing , which is currently expected in fiscal year 2020 . the jv will own and operate the facility under a 25-year contract for a fixed monthly fee . saudi aramco will supply feedstock to the jv , and the jv will produce power , hydrogen and other utilities for saudi aramco . pension benefits the company and certain of its subsidiaries sponsor defined benefit pension plans and defined contribution plans that cover a substantial portion of its worldwide employees . the principal defined benefit pension plans are the u.s . salaried pension plan and the u.k . pension plan . these plans were closed to new participants in 2005 , after which defined contribution plans were offered to new employees . the shift to defined contribution plans is expected to continue to reduce volatility of both plan expense and contributions . the fair market value of plan assets for our defined benefit pension plans as of the 30 september 2018 measurement date decreased to $ 4273.1 from $ 4409.2 at the end of fiscal year 2017 . the projected benefit obligation for these plans was $ 4583.3 and $ 5107.2 at the end of fiscal years 2018 and 2017 , respectively . the net unfunded liability decreased $ 387.8 from $ 698.0 to $ 310.2 , primarily due to higher discount rates and favorable asset experience . refer to note 16 , retirement benefits , to the consolidated financial statements for comprehensive and detailed disclosures on our postretirement benefits . pension expense .

2018: pension expense 2013 continuing operations: 91.8
settlements termination benefits and curtailments ( included above ): 48.9
weighted average discount rate 2013 service cost: -3.2
weighted average discount rate 2013 interest cost: -2.9
weighted average expected rate of return on plan assets: -6.9
weighted average expected rate of compensation increase: -3.5
2017: pension expense 2013 continuing operations: 72
settlements termination benefits and curtailments ( included above ): 15
weighted average discount rate 2013 service cost: -2.9
weighted average discount rate 2013 interest cost: -2.5
weighted average expected rate of return on plan assets: -7.4
weighted average expected rate of compensation increase: -3.5
2016: pension expense 2013 continuing operations: 55.8
settlements termination benefits and curtailments ( included above ): 6
weighted average discount rate 2013 service cost: -4.1
weighted average discount rate 2013 interest cost: -3.4
weighted average expected rate of return on plan assets: -7.5
weighted average expected rate of compensation increase: -3.5

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Questions:
what was the total of operating expenses in 2018?
and what was it in 2017?
how much does the 2018 total of operating expenses represent in relation to this 2017 one?
and what is the difference between this value and the number one?

Answers:
91.8
72.0
1.275
27.5%