continued investments in ecommerce and technology . the increase in operating expenses as a percentage of net sales for fiscal 2017 was partially offset by the impact of store closures in the fourth quarter of fiscal 2016 . membership and other income was relatively flat for fiscal 2018 and increased $ 1.0 billion a0for fiscal 2017 , when compared to the same period in the previous fiscal year . while fiscal 2018 included a $ 387 million gain from the sale of suburbia , a $ 47 million gain from a land sale , higher recycling income from our sustainability efforts and higher membership income from increased plus member penetration at sam's club , these gains were less than gains recognized in fiscal 2017 . fiscal 2017 included a $ 535 million gain from the sale of our yihaodian business and a $ 194 million gain from the sale of shopping malls in chile . for fiscal 2018 , loss on extinguishment of debt was a0$ 3.1 billion , due to the early extinguishment of long-term debt which allowed us to retire higher rate debt to reduce interest expense in future periods . our effective income tax rate was 30.4% ( 30.4 % ) for fiscal 2018 and 30.3% ( 30.3 % ) for both fiscal 2017 and 2016 . although relatively consistent year-over-year , our effective income tax rate may fluctuate from period to period as a result of factors including changes in our assessment of certain tax contingencies , valuation allowances , changes in tax laws , outcomes of administrative audits , the impact of discrete items and the mix of earnings among our u.s . operations and international operations . the reconciliation from the u.s . statutory rate to the effective income tax rates for fiscal 2018 , 2017 and 2016 is presented in note 9 in the "notes to consolidated financial statements" and describes the impact of the enactment of the tax cuts and jobs act of 2017 ( the "tax act" ) to the fiscal 2018 effective income tax rate . as a result of the factors discussed above , we reported $ 10.5 billion and $ 14.3 billion of consolidated net income for fiscal 2018 and 2017 , respectively , which represents a decrease of $ 3.8 billion and $ 0.8 billion for fiscal 2018 and 2017 , respectively , when compared to the previous fiscal year . diluted net income per common share attributable to walmart ( "eps" ) was $ 3.28 and $ 4.38 for fiscal 2018 and 2017 , respectively . walmart u.s . segment .

fiscal years ended january 31 , 2018: net sales: 318477
percentage change from comparable period: -3.5
calendar comparable sales increase: -2.1
operating income: 17869
operating income as a percentage of net sales: -5.6
unit counts at period end: 4761
retail square feet at period end: 705
fiscal years ended january 31 , 2017: net sales: 307833
percentage change from comparable period: -3.2
calendar comparable sales increase: -1.6
operating income: 17745
operating income as a percentage of net sales: -5.8
unit counts at period end: 4672
retail square feet at period end: 699
fiscal years ended january 31 , 2016: net sales: 298378
percentage change from comparable period: -3.6
calendar comparable sales increase: -1
operating income: 19087
operating income as a percentage of net sales: -6.4
unit counts at period end: 4574
retail square feet at period end: 690

net sales for the walmart u.s . segment increased $ 10.6 billion or 3.5% ( 3.5 % ) and $ 9.5 billion or 3.2% ( 3.2 % ) for fiscal 2018 and 2017 , respectively , when compared to the previous fiscal year . the increases in net sales were primarily due to increases in comparable store sales of 2.1% ( 2.1 % ) and 1.6% ( 1.6 % ) for fiscal 2018 and 2017 , respectively , and year-over-year growth in retail square feet of 0.7% ( 0.7 % ) and 1.4% ( 1.4 % ) for fiscal 2018 and 2017 , respectively . additionally , for fiscal 2018 , sales generated from ecommerce acquisitions further contributed to the year-over-year increase . gross profit rate decreased 24 basis points for fiscal 2018 and increased 24 basis points for fiscal 2017 , when compared to the previous fiscal year . for fiscal 2018 , the decrease was primarily due to strategic price investments and the mix impact from ecommerce . partially offsetting the negative factors for fiscal 2018 was the positive impact of savings from procuring merchandise . for fiscal 2017 , the increase in gross profit rate was primarily due to improved margin in food and consumables , including the impact of savings in procuring merchandise and lower transportation expense from lower fuel costs . operating expenses as a percentage of segment net sales was relatively flat for fiscal 2018 and increased 101 basis points for fiscal 2017 , when compared to the previous fiscal year . fiscal 2018 and fiscal 2017 included charges related to discontinued real estate projects of $ 244 million and $ 249 million , respectively . for fiscal 2017 , the increase was primarily driven by an increase in wage expense due to the investment in the associate wage structure ; the charge related to discontinued real estate projects ; and investments in digital retail and technology . the increase in operating expenses as a percentage of segment net sales for fiscal 2017 was partially offset by the impact of store closures in fiscal 2016 . as a result of the factors discussed above , segment operating income increased $ 124 million for fiscal 2018 and decreased $ 1.3 billion for fiscal 2017 , respectively. .

Questions:
what were the net sales in 2018?
and what were they in 2017?
what was, then, the change over the year?
what were the net sales in 2017?
and how much does that change represent in relation to these 2017 net sales, in percentage?

Answers:
318477
307833
10644
307833
3.5%