result of the effects of the costa concordia incident and the continued instability in the european eco- nomic landscape . however , we continue to believe in the long term growth potential of this market . we estimate that europe was served by 102 ships with approximately 108000 berths at the beginning of 2008 and by 117 ships with approximately 156000 berths at the end of 2012 . there are approximately 9 ships with an estimated 25000 berths that are expected to be placed in service in the european cruise market between 2013 and 2017 . the following table details the growth in the global , north american and european cruise markets in terms of cruise guests and estimated weighted-average berths over the past five years : global cruise guests ( 1 ) weighted-average supply of berths marketed globally ( 1 ) north american cruise guests ( 2 ) weighted-average supply of berths marketed in north america ( 1 ) european cruise guests weighted-average supply of berths marketed in europe ( 1 ) .

global cruise guests ( 1 ): 2008: 17184000
2009: 17340000
2010: 18800000
2011: 20227000
2012: 20823000
weighted-average supply of berths marketed globally ( 1 ): 2008: 347000
2009: 363000
2010: 391000
2011: 412000
2012: 425000
north american cruise guests ( 2 ): 2008: 10093000
2009: 10198000
2010: 10781000
2011: 11625000
2012: 12044000
weighted-average supply of berths marketed in north america ( 1 ): 2008: 219000
2009: 222000
2010: 232000
2011: 245000
2012: 254000
european cruise guests: 2008: 4500000
2009: 5000000
2010: 5540000
2011: 5894000
2012: 6040000
weighted-average supply of berths marketed in europe ( 1 ): 2008: 120000
2009: 131000
2010: 143000
2011: 149000
2012: 152000

( 1 ) source : our estimates of the number of global cruise guests , and the weighted-average supply of berths marketed globally , in north america and europe are based on a combination of data that we obtain from various publicly available cruise industry trade information sources including seatrade insider and cruise line international association ( 201cclia 201d ) . in addition , our estimates incorporate our own statistical analysis utilizing the same publicly available cruise industry data as a base . ( 2 ) source : cruise line international association based on cruise guests carried for at least two consecutive nights for years 2008 through 2011 . year 2012 amounts represent our estimates ( see number 1 above ) . ( 3 ) source : clia europe , formerly european cruise council , for years 2008 through 2011 . year 2012 amounts represent our estimates ( see number 1 above ) . other markets in addition to expected industry growth in north america and europe as discussed above , we expect the asia/pacific region to demonstrate an even higher growth rate in the near term , although it will continue to represent a relatively small sector compared to north america and europe . competition we compete with a number of cruise lines . our princi- pal competitors are carnival corporation & plc , which owns , among others , aida cruises , carnival cruise lines , costa cruises , cunard line , holland america line , iberocruceros , p&o cruises and princess cruises ; disney cruise line ; msc cruises ; norwegian cruise line and oceania cruises . cruise lines compete with other vacation alternatives such as land-based resort hotels and sightseeing destinations for consumers 2019 leisure time . demand for such activities is influenced by political and general economic conditions . com- panies within the vacation market are dependent on consumer discretionary spending . operating strategies our principal operating strategies are to : 2022 protect the health , safety and security of our guests and employees and protect the environment in which our vessels and organization operate , 2022 strengthen and support our human capital in order to better serve our global guest base and grow our business , 2022 further strengthen our consumer engagement in order to enhance our revenues , 2022 increase the awareness and market penetration of our brands globally , 2022 focus on cost efficiency , manage our operating expenditures and ensure adequate cash and liquid- ity , with the overall goal of maximizing our return on invested capital and long-term shareholder value , 2022 strategically invest in our fleet through the revit ad alization of existing ships and the transfer of key innovations across each brand , while prudently expanding our fleet with the new state-of-the-art cruise ships recently delivered and on order , 2022 capitalize on the portability and flexibility of our ships by deploying them into those markets and itineraries that provide opportunities to optimize returns , while continuing our focus on existing key markets , 2022 further enhance our technological capabilities to service customer preferences and expectations in an innovative manner , while supporting our strategic focus on profitability , and part i 0494.indd 13 3/27/13 12:52 pm .

Questions:
what is the average number of berths per ship in 2008?
what about in 2012?
what is the difference?

Answers:
1058.82
1333.33
274.51