pre_text: Year Ended December 31, 2018 Compared to the Year Ended December 31, 2017 Our management reviews and analyzes several key financial measures in order to manage our business and assess the quality of and variability of our service revenue, operating results and cash flows. The following summary tables present a comparison of our results of operations with respect to certain key financial measures. The comparisons illustrated in the tables are discussed in greater detail below.
table: Year Ended December 31,
table: 2018 2017 Change
table: Other Operating Data
table: Average Revenue Per Unit (ARPU)
table: ARPU—on-net $ 480 $ 506 (5.1)%
table: ARPU—off-net $ 1,155 $ 1,239 (6.8)%
table: Average price per megabit $ 0.82 $ 1.11 (25.9)%
table: Customer Connections—end of period
table: On-net 68,770 61,334 12.1%
table: Off-net 10,974 9,953 10.3%
question: Analyse this data from a financial earnings document. What is the percentage change in the number of on-net customer connections between 2017 and 2018?